12
Resource Locker A2.7.I Write the domain and range of a function in interval notation, inequalities, and set notation. © Houghton Mifflin Harcourt Publishing Company Name Class Date Explore Representing an Interval on a Number Line An interval is a part of a number line without any breaks. A finite interval has two endpoints, which may or may not be included in the interval. An infinite interval is unbounded at one or both ends. Suppose an interval consists of all real numbers greater than or equal to 1. You can use the inequality x 1 to represent the interval. You can also use set notation and interval notation, as shown in the table. Description of Interval Type of Interval Inequality Set Notation Interval notation All real numbers from a to b, including a and b Finite a x b {x|a x b} [a, b] All real numbers greater than a Infinite x > a {x|x > a} (a, +∞) All real numbers less than or equal to a Infinite x a {x|x a} (-∞, a] For set notation, the vertical bar means “such that,” so you read {x|x 1} as “the set of real numbers x such that x is greater than or equal to 1.” For interval notation, do the following: Use a square bracket to indicate that an interval includes an endpoint and a parenthesis to indicate that an interval doesn’t include an endpoint. For an interval that is unbounded at its positive end, use the symbol for positive infinity, +. For an interval that unbounded at its negative end, use the symbol for negative infinity, -. Always use a parenthesis with positive or negative infinity. So, you can write the interval x 1 as [1, +∞). Complete the table by writing the finite interval shown on each number line as an inequality, using set notation, and using interval notation. Finite Interval 012345 -1 -2 -3 -4 -5 012345 -1 -2 -3 -4 -5 Inequality Set Notation Interval Notation -3 x 2 {x|-3 x 2} [-3, 2] -3 < x 2 {x|-3 < x 2} ( -3, 2] Module 1 5 Lesson 1 1.1 Domain, Range, and End Behavior Essential Question: How can you determine the domain, range, and end behavior of a function? Texas Math Standards The student is expected to: A2.7.1 Write the domain and range of a function in interval notation, inequalities, and set notation. Mathematical Processes A2.1.D The student is expected to communicate mathematical ideas, reasoning, and their implications using multiple representations, including symbols, diagrams, graphs, and language as appropriate. Language Objective 1.C.1, 1.E.1, 1.E.2, 2.C.2, 2.C.4 With a partner, fill in a graphic organizer showing the domain, range, and end behavior of a function. HARDCOVER PAGES 512 Turn to these pages to find this lesson in the hardcover student edition. Domain, Range, and End Behavior ENGAGE Essential Question: How can you determine the domain, range, and end behavior of a function? Possible answer: The domain consists of x values for which the function is defined or on which the real-world situation is based. The range consists of the corresponding f (x) values. The end behavior describes what happens to the f (x) values as the x values increase without bound or decrease without bound. PREVIEW: LESSON PERFORMANCE TASK View the online Engage. Discuss how the distance a car can travel is a function of the amount of gas in the car’s gas tank. Have students identify the independent and dependent variables of the functional relationship. Then preview the Lesson Performance Task. Resource Locker A2.7.I Write the domain and range of a function in interval notation, inequalities, and set notation. © Houghton Mifflin Harcourt Publishing Company Name Class Date Explore Representing an Interval on a Number Line An interval is a part of a number line without any breaks. A finite interval has two endpoints, which may or may not be included in the interval. An infinite interval is unbounded at one or both ends. Suppose an interval consists of all real numbers greater than or equal to 1. You can use the inequality x1 to represent the interval. You can also use set notationand interval notation, as shown in the table. Description of Interval Type of Interval Inequality Set Notation Interval notation All real numbers from ato b, including aand b Finite axb {x|axb} [a, b] All real numbers greater than a Infinite x>a {x|x>a} (a, +∞) All real numbers less than or equal to a Infinite xa {x|xa} (-∞, a] For set notation, the vertical bar means “such that,” so you read {x|x1} as “the set of real numbers xsuch that xis greater than or equal to 1.” For interval notation, do the following: Use a square bracket to indicate that an interval includes an endpoint and a parenthesis to indicate that an interval doesn’t include an endpoint. For an interval that is unbounded at its positive end, use the symbol for positive infinity, +. For an interval that unbounded at its negative end, use the symbol for negative infinity, -. Always use a parenthesis with positive or negative infinity. So, you can write the interval x1 as [1, +∞). Complete the table by writing the finite interval shown on each number line as an inequality, using set notation, and using interval notation. Finite Interval 012345 -1 -2 -3 -4 -5 012345 -1 -2 -3 -4 -5 Inequality Set Notation Interval Notation -3 x2 {x|-3 x2} [-3, 2] -3 <x2 {x|-3 <x2} ( -3, 2] Module 1 5 Lesson 1 1.1 Domain, Range, and End Behavior Essential Question: How can you determine the domain, range, and end behavior of a function? DO NOT EDIT--Changes must be made through "File info" CorrectionKey=TX-A 5 Lesson 1.1 LESSON 1.1

CorrectionKey=TX-A CorrectionKey=TX-B LESSON 1 . 1 …€¦ ·  · 2017-01-05A2.7.1 Write the domain and range of a function in interval notation, inequalities, and set notation

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Page 1: CorrectionKey=TX-A CorrectionKey=TX-B LESSON 1 . 1 …€¦ ·  · 2017-01-05A2.7.1 Write the domain and range of a function in interval notation, inequalities, and set notation

Resource Locker

A27I Write the domain and range of a function in interval notation inequalities and set notation

copy H

oug

hton

Mif

flin

Har

cour

t Pub

lishi

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Com

pan

y

Name Class Date

Explore Representing an Interval on a Number LineAn interval is a part of a number line without any breaks A finite interval has two endpoints which may or may not be included in the interval An infinite interval is unbounded at one or both ends

Suppose an interval consists of all real numbers greater than or equal to 1 You can use the inequality x ge 1 to represent the interval You can also use set notation and interval notation as shown in the table

Description of Interval Type of Interval Inequality Set Notation Interval notation

All real numbers from a to b including a and b

Finite a le x le b x|a le x le b [a b]

All real numbers greater than a Infinite x gt a x|x gt a (a +infin)

All real numbers less than or equal to a

Infinite x le a x|x le a (minusinfin a]

For set notation the vertical bar means ldquosuch thatrdquo so you read x|x ge 1 as ldquothe set of real numbers x such that x is greater than or equal to 1rdquo

For interval notation do the following

bull Use a square bracket to indicate that an interval includes an endpoint and a parenthesis to indicate that an interval doesnrsquot include an endpoint

bull For an interval that is unbounded at its positive end use the symbol for positive infinity +infin For an interval that unbounded at its negative end use the symbol for negative infinity -infin Always use a parenthesis with positive or negative infinity

So you can write the interval x ge 1 as [1 +infin)

Complete the table by writing the finite interval shown on each number line as an inequality using set notation and using interval notation

Finite Interval 0 1 2 3 4 5-1-2-3-4-5 0 1 2 3 4 5-1-2-3-4-5

Inequality

Set Notation

Interval Notation

minus3 le x le 2

x|minus3 le x le 2

[minus3 2]

minus3 lt x le 2

x|minus3 lt x le 2

( minus3 2]

Module 1 5 Lesson 1

1 1 Domain Range and End Behavior

Essential Question How can you determine the domain range and end behavior of a function

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-A

A2_MTXESE353930_U1M01L1indd 5 22214 304 AM

Texas Math StandardsThe student is expected to

A271

Write the domain and range of a function in interval notation inequalities and set notation

Mathematical Processes

A21D

The student is expected to communicate mathematical ideas reasoning and their implications using multiple representations including symbols diagrams graphs and language as appropriate

Language Objective

1C1 1E1 1E2 2C2 2C4

With a partner fill in a graphic organizer showing the domain range and end behavior of a function

HARDCOVER PAGES 512

Turn to these pages to find this lesson in the hardcover student edition

Domain Range and End Behavior

ENGAGE Essential Question How can you determine the domain range and end behavior of a functionPossible answer The domain consists of x values for

which the function is defined or on which the

real-world situation is based The range consists of

the corresponding f (x) values The end behavior

describes what happens to the f (x) values as the x

values increase without bound or decrease

without bound

PREVIEW LESSON PERFORMANCE TASKView the online Engage Discuss how the distance a car can travel is a function of the amount of gas in the carrsquos gas tank Have students identify the independent and dependent variables of the functional relationship Then preview the Lesson Performance Task

5

HARDCOVER PAGES

Turn to these pages to find this lesson in the hardcover student edition

Resource

Locker

A27I Write the domain and range of a function in interval notation inequalities and set

notation

copy H

ough

ton

Mif

flin

Har

cour

t Pub

lishi

ng C

omp

any

Name

Class Date

Explore Representing an Interval on a Number Line

An interval is a part of a number line without any breaks A finite interval has two endpoints which may or may not

be included in the interval An infinite interval is unbounded at one or both ends

Suppose an interval consists of all real numbers greater than or equal to 1 You can use the inequality x ge 1 to

represent the interval You can also use set notation and interval notation as shown in the table

Description of Interval Type of Interval Inequality Set Notation Interval notation

All real numbers from a to b

including a and b

Finitea le x le b x|a le x le b

[a b]

All real numbers greater than aInfinite

x gt ax|x gt a

(a +infin)

All real numbers less than or

equal to a

Infinitex le a

x|x le a(minusinfin a]

For set notation the vertical bar means ldquosuch thatrdquo so you read x|x ge 1 as ldquothe set of real numbers x such

that x is greater than or equal to 1rdquo

For interval notation do the following

bull Use a square bracket to indicate that an interval includes an endpoint and a parenthesis to indicate

that an interval doesnrsquot include an endpoint

bull For an interval that is unbounded at its positive end use the symbol for positive infinity +infin

For an interval that unbounded at its negative end use the symbol for negative infinity -infin

Always use a parenthesis with positive or negative infinity

So you can write the interval x ge 1 as [1 +infin)

Complete the table by writing the finite interval shown on each number line as an

inequality using set notation and using interval notation

Finite Interval0 1 2 3 4 5

-1-2-3-4-5

0 1 2 3 4 5-1-2-3-4-5

Inequality

Set Notation

Interval

Notation

minus3 le x le 2

x|minus3 le x le 2

[minus3 2]

minus3 lt x le 2

x|minus3 lt x le 2

( minus3 2]

Module 1

5

Lesson 1

1 1 Domain Range

and End Behavior

Essential Question How can you determine the domain range and end behavior of a

function

DO NOT EDIT--Changes must be made through File info

CorrectionKey=TX-A

A2_MTXESE353930_U1M01L1indd 5

22214 304 AM

5 Lesson 1 1

L E S S O N 1 1

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-2-4

-2 -1 0 54321-3-5 -4

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B Complete the table by writing the infinite interval shown on each number line as an inequality using set notation and using interval notation

Infinite Interval 1 2 3 4 50-5 -4 -3 -2 -1 1 2 3 4 50-5 -4 -3 -2 -1

Inequality

Set Notation

Interval Notation

Reflect

1 Consider the interval shown on the number line

a Represent the interval using interval notation

b What numbers are in this interval

2 What do the intervals [0 5] [0 5) and (0 5) have in common What makes them different

3 Discussion The symbol cup represents the union of two sets What do you think the notation (-infin 0) cup (0 + infin) represents

Explain 1 Identifying a Functionrsquos Domain Range and End Behavior from its Graph

Recall that the domain of a function f is the set of input values x and the range is the set of output values ƒ(x) The end behavior of a function describes what happens to the ƒ(x)-values as the x-values either increase without bound (approach positive infinity) or decrease without bound (approach negative infinity) For instance consider the graph of a linear function shown From the graph you can make the following observations

All three intervals contain all the numbers between 0 and 5 The interval [0 5] also

includes the endpoints 0 and 5 the interval [0 5) includes only the endpoint 0 and the

interval (0 5) does not contain either endpoint

All real numbers except 0

(minusinfin +infin)

All real numbers

x le 2

x|x le 2

(minusinfin 2]

x gt 2

x|x gt 2

(2 +infin)

Module 1 6 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-A

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-A

A2_MTXESE353930_U1M01L1indd 6 22214 304 AM

Integrate Mathematical ProcessesThis lesson provides an opportunity to address Mathematical Process TEKS A21D which calls for students to ldquocommunicate mathematical ideas reasoning and their implications using multiple representations including symbols diagrams graphs and language as appropriaterdquo Students learn to describe intervals using inequalities set notation and interval notation They also learn how to use mathematical notation to describe the end behavior of a function

EXPLORE Representing an Interval on a Number Line

INTEGRATE TECHNOLOGYStudents have the option of completing the activity either in the book or online

INTEGRATE MATHEMATICAL PROCESSESFocus on ModelingDraw studentsrsquo attention to the use of braces parentheses and brackets in the various representations Make sure students can use the symbols correctly and can explain the significance of the symbols in each type of notation

EXPLAIN 1 Identifying a Functionrsquos Domain Range and End Behavior from its Graph

AVOID COMMON ERRORSSome students may incorrectly identify the end behavior of a function that increases over the interval (-infin 0) as ldquoAs x rarr -infin ƒ (x) rarr infinrsquorsquo Help students to see that for this part of the description they must consider the behavior of the function as the values of x decrease (the behavior of the graph as observed from right to left) and not whether the function itself is an increasing or decreasing functionPROFESSIONAL DEVELOPMENT

Domain Range and End Behavior 6

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-2-4

-4

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Statement of End Behavior Symbolic Form of Statement

As the x-values increase without bound the f(x)-values also increase without bound

As x rarr +infin f(x) rarr +infin

As the x-values decrease without bound the f(x)-values also decrease without bound

As x rarr -infin f(x) rarr -infin

Example 1 Write the domain and the range of the function as an inequality using set notation and using interval notation Also describe the end behavior of the function

The graph of the quadratic function f(x) = x2 is shown

Domain

Inequality minusinfin lt x lt +infin

Set notation x| minusinfin lt x lt +infin

Interval notation (minusinfin +infin)

Range End behavior

Inequality y ge 0 As x rarr +infin f(x) rarr +infin

Set notation y|y ge 0 As x rarr minusinfin f(x) rarr +infin

Interval notation [0 +infin)

The graph of the exponential function ƒ(x) = 2 x is shown

Domain

Inequality

Set notation

Interval notation

Range

Inequality

Set notation

Interval notation

End behavior

As x rarr +infin

As x rarr +infin

minusinfin lt x lt +infin

x| minusinfin lt x lt +infin

(minusinfin +infin)

y gt 0

y|y gt 0

(0 +infin)

f(x) rarr +infin

f(x) rarr 0

Module 1 7 Lesson 1

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-A

A2_MTXESE353930_U1M01L1indd 7 22214 304 AM

COLLABORATIVE LEARNING

Peer-to-Peer ActivityHave students work in pairs to draw the graph of a linear function with a restricted domain and keep the graph hidden from their partner Have students describe the functionrsquos domain and range using one of the notation forms from the lesson then exchange descriptions and try to draw each otherrsquos graph Have students compare their graphs (which may differ) and discuss the results

QUESTIONING STRATEGIESIs it possible that a linear function with the domain all real numbers could have a range

that is not all real numbers Explain Yes the

function could be a constant function such as

f (x) = 2 The domain is all real numbers but the

range is 2

7 Lesson 1 1

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

-4

-2

4

2

y

0 42

x

-2-4

-2

4

6

2

y

0 42

x

-2

copy H

oug

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arcourt Publishin

g Com

pany

Reflect

4 Why is the end behavior of a quadratic function different from the end behavior of a linear function

5 In Part B the ƒ(x)-values decrease as the x-values decrease So why canrsquot you say that f(x) rarr minusinfin as x rarr minusinfin

Your Turn

Write the domain and the range of the function as an inequality using set notation and using interval notation Also describe the end behavior of the function

6 The graph of the quadratic function ƒ(x) = minusx2 is shown

Explain 2 Graphing a Linear Function on a Restricted Domain

Unless otherwise stated a function is assumed to have a domain consisting of all real numbers for which the function is defined Many functionsmdashsuch as linear quadratic and exponential functionsmdashare defined for all real numbers so their domain when written in interval notation is (-infin +infin) Another way to write the set of real numbers is ℝ

Sometimes a function may have a restricted domain If the rule for a function and its restricted domain are given you can draw its graph and then identify its range

Example 2 For the given function and domain draw the graph and identify the range using the same notation as the given domain

ƒ(x) = 3 __ 4 x +2 with domain [-4 4]

Since ƒ(x) = 3 __ 4 x +2 is a linear function the graph is a line segment with endpoints at (-4 ƒ(-4)) or (-4 -1) and (4 ƒ(4)) or (4 5) The endpoints are included in the graph

The range is [-1 5]

Unlike the graph of a linear function the graph of a quadratic function has a turning point

(the vertex) which changes the direction of the graph

The f(x)-values do not decrease without bound They instead approach 0

Domain minusinfin lt x lt +infin x| minusinfin lt x lt +infin (minusinfin +infin)

Range y| y le0 (minusinfin 0]

End behavior As x rarr +infin f(x) rarr -infin As x rarr -infin f(x) rarr -infin

Module 1 8 Lesson 1

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 8 21415 954 PM

EXPLAIN 2 Graphing a Linear Function on a Restricted Domain

INTEGRATE MATHEMATICAL PROCESSESFocus on Math ConnectionsRemind students that the graph of a function represents the set of ordered pairs produced by the function Help them to see that when they are using a graph to identify the range of a function they are to identify the y-values of those ordered pairs

DIFFERENTIATE INSTRUCTION

Cognitive StrategiesIf students have a difficult time consistently identifying the domain and range of functions encourage them to use the phrase depends on instead of is a function of For example ldquoThe distance traveled by a car depends on the amount of gas in the tankrdquo Help them to see that the elements of the range ldquodepend onrdquo the elements of the domain

Domain Range and End Behavior 8

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

-4

-2

4

2

y

0 42

x

-2-4

4

6

2

y

0 2

x

-2-4-6 -4

-2

4

2

y

0 42

x

-2-4

copy H

oug

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y

Bƒ(x) = -x - 2 with domain x|x gt -3

Since ƒ(x) = -x -2 is a linear function the graph is a ray with its endpoint at (-3 ƒ(-3)) or

The endpoint included in the graph

The range is

Reflect

7 In Part A how does the graph change if the domain is (-4 4) instead of [-4 4]

8 In Part B what is the end behavior as x increases without bound Why canrsquot you talk about the end behavior as x decreases without bound

Your Turn

For the given function and domain draw the graph and identify the range using the same notation as the given domain

9 ƒ(x) = - 1 _ 2 x + 2 with domain -6 le x lt 2 10 f(x) = 2 _ 3 x -1 with domain (minusinfin 3]

(-3 1)

is not

y|y lt 1

The graph no longer includes the endpoints of the segment

As x rarr +infin f(x) rarr -infin Because the domain does not include values of x that are less

than or equal to -3 the values of x cannot decrease without bound

The range is 1 lt y le 5 The range is (minusinfin 1]

Module 1 9 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 9 11415 241 AM

LANGUAGE SUPPORT

Connect VocabularyHave students work in pairs Instruct one student to verbally describe the domain range and end behavior of a function without using those three terms Have the other student fill in a graphic organizer with boxes titled Domain Range and End behavior and write in the appropriate values under each box Have students switch roles and repeat the exercise using a different function

QUESTIONING STRATEGIESIf a linear function has a restricted domain must the range consist of a finite number of

elements Explain No If the domain is restricted to

an interval (or intervals) as opposed to a finite

number of elements the range could consist of

infinitely many values For example the range of

the function f (x) = 3x with domain ⎡ ⎣ 0 5 ⎤ ⎦ is ⎡ ⎣ 0 15 ⎤ ⎦

an interval containing infinitely many numbers

If the domain of a linear function consists of n elements how many elements would there be

in the range Explain One if the function is a

constant function or n if it is not In a non-constant

linear function each element of the domain is

paired with a different element of the range

9 Lesson 1 1

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

0

1

2

3

4

Time (min)

Dis

tanc

e (m

i)

d

t

40302010

0

2

4

6

8

1

3

5

7

Time (h)

Hei

ght (

in)

h

t

4321 8765

copy H

oug

hton Mifflin H

arcourt Publishin

g Com

pany bull Im

age C

redits copy

Bounce

Up

perC

ut Imag

esGetty Im

ages

Explain 3 Modeling with a Linear FunctionRecall that when a real-world situation involves a constant rate of change a linear function is a reasonable model for the situation The situation may require restricting the functionrsquos domain

Example 3 Write a function that models the given situation Determine a domain from the situation graph the function using that domain and identify the range

Joyce jogs at a rate of 1 mile every 10 minutes for a total of 40 minutes (Use inequalities for the domain and range of the function that models this situation)

Joycersquos jogging rate is 01 mimin Her jogging distance d (in miles) at any time t (in minutes) is modeled by d(t) = 01t Since she jogs for 40 minutes the domain is restricted to the interval 0 le t le 40

The range is 0 le d le 4

A candle 6 inches high burns at a rate of 1 inch every 2 hours for 5 hours (Use interval notation for the domain and range of the function that models this situation)

The candlersquos burning rate is inh The candlersquos height h (in inches) at any time t (in hours) is modeled by h(t) =

Since the candle burns for 5 hours the domain is restricted to the

interval ⎡

⎢ ⎣ 0

⎥ ⎦

The range is

-05

6 - 05t

5

[35 6]

Module 1 10 Lesson 1

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 10 11215 430 PM

EXPLAIN 3 Modeling with a Linear Function

AVOID COMMON ERRORSSome students may erroneously identify the domain of a function that represents a real-world situation as an interval when in fact the domain consists only of specific numbers within the interval such as integers or multiples of a particular rational number Help students to avoid this error by encouraging them to ask themselves whether any number within the interval could be a realistic input value for the situation described by the function

INTEGRATE MATHEMATICAL PROCESSESFocus on ReasoningEncourage students to check their work by considering the reasonableness of the range of the function Have them evaluate whether the values in the range seem realistic for the given situation

Domain Range and End Behavior 10

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

0

20

40

60

80

10

30

50

70

10090

Time (s)

Dis

tanc

e on

wal

kway

(ft)

d

t

80604020

copy H

oug

hton

Mif

flin

Har

cour

t Pub

lishi

ng

Com

pan

y

Reflect

11 In Part A suppose Joyce jogs for only 30 minutes

A How does the domain change

B How does the graph change

C How does the range change

Your Turn

12 While standing on a moving walkway at an airport you are carried forward 25 feet every 15 seconds for 1 minute Write a function that models this situation Determine the domain from the situation graph the function and identify the range Use set notation for the domain and range

Elaborate

13 If a and b are real numbers such that a lt b use interval notation to write four different intervals having a and b as endpoints Describe what numbers each interval includes

14 What impact does restricting the domain of a linear function have on the graph of the function

15 Essential Question Check-In How does slope determine the end behavior of a linear function with an unrestricted domain

The domain is 0 le t le 30 instead of 0 le t le 40

The graphrsquos right endpoint is (30 3) instead of (40 4)

The range is 0 le d le 3 instead of 0 le d le 4

The walkwayrsquos rate of motion is 5 __ 3 fts The distance d (in feet)

you travel at any time t (in seconds) is modeled by d(t) = 5 __ 3 t

Domain t| 0 le t le 60 range d| 0 le d le 100

[a b] This interval includes all real numbers between a and b including both a and b

[a b) This interval includes all real numbers between a and b including a but not b

(a b] This interval includes all real numbers between a and b including b but not a

(a b) This interval includes all real numbers between a and b but does not include a or b

If slope is positive the f(x)-values increase without bound as the x-values increase without

bound and the f(x)-values decrease without bound as the x-values decrease without bound

If the slope is negative the end behavior reverses The f(x)-values decrease without bound

as the x-values increase without bound and the f(x)-values increase without bound as the

x-values decrease without bound

If the domain is bounded at both ends the graph of the linear function is a line segment

rather than a line If the domain is bounded at only one end the graph of the linear function

is a ray rather than a line

Module 1 11 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 11 11415 241 AM

ELABORATE INTEGRATE MATHEMATICAL PROCESSESFocus on CommunicationDiscuss different strategies for determining the range of a function from a graph of the function Have students describe methods they use and illustrate their methods using graphs of different types of functions including those with restricted domains

QUESTIONING STRATEGIESIs it possible that a real-world situation can be modeled by a function whose domain consists

of both positive and negative real numbers If no explain why not If yes give an example Yes

Possible example a function that describes the

relationship between air temperature in degrees

Fahrenheit and dew point at a given level of

humidity The domain consists of all possible air

temperatures in degrees Fahrenheit

SUMMARIZE THE LESSONHow do you identify and represent the domain range and end behavior of a

function To identify the domain find the values of

x for which the function is defined To find the

range find the values of f (x) for each value of x in

the domain There are different ways of

representing the domain and range including using

inequalities set notation and interval notation To

find the end-behavior consider what happens to

the values of the range as the values of the domain

increase or decrease without bound

11 Lesson 1 1

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bull Online Homeworkbull Hints and Helpbull Extra Practice

1 Write the interval shown on the number line as an inequality using set notation and using interval notation

2 Write the interval (5 100] as an inequality and using set notation

3 Write the interval -25 le x lt 30 using set notation and interval notation

4 Write the interval x| -3 lt x lt 5 as an inequality and using interval notation

Write the domain and the range of the function as an inequality using set notation and using interval notation Also describe the end behavior of the function or explain why there is no end behavior

5 The graph of the quadratic functionf (x) = x 2 + 2 is shown

6 The graph of the exponential function f (x) = 3 x is shown

Evaluate Homework and Practice

x ge 5 x|x ge 5 [5 +infin)

x| -25 le x lt 30 [-25 30)

5 lt x le 100 x|5 lt x le 100

-3 lt x lt 5 (-3 5)

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range 2 le y lt +infin y⎪ 2 le y lt +infin ⎡ ⎣ 2 +infin)End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr +infin

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range 0 lt y lt +infin y⎪ 0 lt y lt +infin (0 +infin)End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr 0

Module 1 12 Lesson 1

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A2_MTXESE353930_U1M01L1indd 12 22214 304 AMExercise Depth of Knowledge (DOK) Mathematical Processes

1ndash8 1 Recall of Information 1F Analyze relationships

9ndash10 1 Recall of Information 1E Create and use representations

11 1 Recall of Information 1D Multiple representations

12 2 SkillsConcepts 1A Everyday life

13 2 SkillsConcepts 1G Explain and justify arguments

14 3 Strategic Thinking 1D Multiple representations

EVALUATE

ASSIGNMENT GUIDE

Concepts and Skills Practice

ExploreRepresenting an Interval on a Number Line

Exercise 1ndash4

Example 1Identifying a Functionrsquos Domain Range and End Behavior from its Graph

Exercises 5ndash8

Example 2Graphing a Linear Function on a Restricted Domain

Exercises 9ndash10

Example 3Modeling with a Linear Function

Exercises 11ndash12

VISUAL CUESSome students may benefit from labeling the endpoints of an interval as included or not included as indicated by the closed circle or open circle on the graph They will then be sure to use the appropriate symbols when describing the interval using the different types of notation

CONNECT VOCABULARY Relate end behavior to the shape of the graph of different functions Have students use words to describe the end behavior of each function by looking at the graph For example a function ƒ (x) appears to rise for positive x-values and fall for negative x-values

Domain Range and End Behavior 12

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0 42

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-2

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7 The graph of the linear function g (x) = 2x - 2 is shown

8 The graph of a function is shown

For the given function and domain draw the graph and identify the range using the same notation as the given domain

9 f(x) = minusx + 5 with domain [minus3 2] 10 f(x) = 3 _ 2 x + 1 with domain x |x gt minus 2

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range minusinfin lt y lt +infin y⎪ minusinfin lt y lt +infin (minusinfin +infin) End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr -infin

Domain minus4 le x le 4 x⎪ minus4 le x le 4 [minus4 4]

Range 0 le y le 4 y⎪ 0 le y le 4 [0 4]

There is no end behavior because the domain is bounded at both ends

Since f (x) = -x + 5 is a linear

function the graph is a line

segment with endpoints at

(-3 f (-3) ) or (minus3 8) and

(2 f(2)) or (2 3) The endpoints

are included in the graph

The range is [3 8]

Since f (x) = 3 _ 2

x + 1 is a linear

function the graph is a ray with

its endpoint at (-2 f (-2) )

or (minus2 minus2) The endpoint is not

included in the graph

The range is y⎪ y gt - 2

Module 1 13 Lesson 1

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A2_MTXESE353930_U1M01L1indd 13 11415 241 AMExercise Depth of Knowledge (DOK) Mathematical Processes

15 2 SkillsConcepts 1E Create and use representations

MULTIPLE REPRESENTATIONSWhen analyzing the graph of a function students may find it easier to first describe the end behavior of the function in words They then can translate their verbal descriptions into algebraic notation making sure that the symbols accurately reflect their descriptions

KINESTHETIC EXPERIENCETo help students correctly identify end behavior suggest that they use a finger to trace along the graph of a function moving first from left to right as x rarr infin and then from right to left as x rarr -infin Help them to match their observations of the behavior of the graph to its correct description and notation

13 Lesson 1 1

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CaroA

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Write a function that models the given situation Determine the domain from the situation graph the function using that domain and identify the range

11 A bicyclist travels at a constant speed of 12 miles per hour for a total of 45 minutes (Use set notation for the domain and range of the function that models this situation)

12 An elevator in a tall building starts at a floor of the building that is 90 meters above the ground The elevator descends 2 meters every 05 second for 6 seconds (Use an inequality for the domain and range of the function that models this situation)

HOT Focus on Higher Order Thinking

13 Explain the Error Cameron sells tickets at a movie theater On Friday night she worked from 4 pm to 10 pm and sold about 25 tickets every hour Cameron says that the number of tickets n she has sold at any time t (in hours) can be modeled by the function n(t) = 25t where the domain is 0 le t le 1 and the range is 0 le n le 25 Is Cameronrsquos function along with the domain and range correct Explain

The bicyclistrsquos speed is 12 mih The distance traveled

d (in miles) at any time t (in hours) is modeled by

d(t) = 12t Since the bicyclist travels for 45 minutes

or 075 hour the domain is restricted to the interval

t⎪0 le t le 075

The range is d⎪0 le d le 9

The elevatorrsquos rate of motion is -4 ms The elevatorrsquos

height h (in meters) at any time t (in seconds) is modeled by

h(t) = 90 - 4t Since the elevator descends for 6 seconds

the domain is restricted to the interval 0 le t le 6

The range is 66 le h le 90

Cameronrsquos function is correct but the domain and range are incorrect Cameron worked for a total of 6 hours so the domain of the function should be 0 le t le 6 After 6 hours Cameron has sold 25 times 6 = 150 tickets So the range of the function should be 0 le n le 150

Module 1 14 Lesson 1

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A2_MTXESE353930_U1M01L1indd 14 11415 241 AM

QUESTIONING STRATEGIESWhen is the graph of a linear function with a restricted domain a line segment When is it a

ray It is a line segment when the domain is a

closed interval It is a ray when the domain is

restricted to real numbers greater than or equal to a

number or less than or equal to a number

AVOID COMMON ERRORSWhen attempting to model a real-world situation students sometimes confuse the dependent and independent variables thus reversing the domain and range Help them to understand that the domain consists of the values represented by the independent variable and that the range values are a function of the values of the domain

Domain Range and End Behavior 14

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50

-100

-50

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0

200

400

600

800

Distance from tower (ft)

Hei

ght a

bove

bri

dge

deck

(ft)

y

x

400200 800 1000600

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14 Multi-Step The graph of the cubic function ƒ(x) = x 3 is shown

a What are the domain range and end behavior of the function (Write the domain and range as an inequality using set notation and using interval notation)

b How is the range of the function affected if the domain is restricted to [-4 4] (Write the range as an inequality using set notation and using interval notation)

c Graph the function with the restricted domain

15 Represent Real-World Situations The John James Audubon Bridge is a cable-stayed bridge in Louisiana that opened in 2011 The height from the bridge deck to the top of the tower where a particular cable is anchored is about 500 feet and the length of that cable is about 1200 feet Draw the cable on a coordinate plane letting the x-axis represent the bridge deck and the y-axis represent the tower (Only use positive values of x and y) Write a linear function whose graph models the cable Identify the domain and range writing each as an inequality using set notation and using interval notation

a Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range minusinfin lt y lt +infin y⎪ minusinfin lt y lt +infin (minusinfin +infin) End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr -infin

b Restricted range -64 le y le 64 y⎪ minus64 le y le +64 [-64 64]

c

Since the cable the bridge deck and the

tower form a right triangle find the length

of the leg that lies on the x-axis by using the

Pythagorean Theorem

a 2 + b 2 = c 2

500 2 + b 2 = 1200 2

b asymp 109 1

slope m = 500 - 0 _ 0 - 1091

= 500 _ -1091 asymp -046

The y-intercept is 500

So the linear function is y = -046x + 500

Domain 0 le x le 1091 x⎪0 le x le 1091 [0 1091]

Range 0 le y le 500 y⎪0 le y le 500 [0 500]

Module 1 15 Lesson 1

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A2_MTXESE353930_U1M01L1indd 15 11415 241 AM

PEERTOPEER DISCUSSIONIs it possible that a linear function with the domain all real numbers could have a range that is not all real numbers Explain Yes the function could be a

constant function such as f (x) = 2 The domain is

all real numbers but the range is 2

You may want to have students work on the modeling questions in pairs thus providing them with an opportunity to discuss each situation with a partner and decide how to best model the situation using a function

JOURNALHave students describe how to identify the domain and range of a function given its graph or given the situation it models

15 Lesson 1 1

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0

100

200

300

400450500550

50

150

250

350

Gas used (gal)

Dis

tanc

e tr

avel

ed (m

i)

d

g

161284

20122007

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The fuel efficiency for a 2007 passenger car was 312 migal For the same model of car the fuel efficiency increased to 356 migal in 2012 The gas tank for this car holds 16 gallons of gas

a Write and graph a linear function that models the distance that each car can travel for a given amount of gas (up to one tankful)

b Write the domain and range of each function using interval notation

c Write and simplify a function ƒ (g) that represents the difference in the distance that the 2012 car can travel and the distance that the 2007 car can travel on the same amount of gas Interpret this function using the graphs of the functions from part a Also find and interpret ƒ (16)

d Write the domain and range of the difference function using set notation

Lesson Performance Task

a For both cars let g be the amount of gas (in gallons) that each car uses and let d be the distance (in miles) that each car travels For the 2007 car the linear model is d 2007 (g) = 312g For the 2012 car the linear model is d 2012 (g) = 356g

b The domain for the 2007 model is [0 16] and the range is [0 4992] The domain for the 2012 model is [0 16] and the range is [0 5696]

c The difference function is f(g) = d 2012 (g) minus d 2007 (g) = 356g minus 312g = 44g This function gives the vertical distance between the graphs of d 2012 (g) and d 2007 (g) For instance when g = 16 the vertical distance between the graphs is f(16) = 44 16 = 704 which means the 2012 car can travel 704 miles farther on a tankful of gas than the 2007 car

d The domain is g⎪0 le g le 16 and the range is f(g)⎪0 le f(g) le 704

Module 1 16 Lesson 1

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A2_MTXESE353930_U1M01L1indd 16 22214 319 AM

EXTENSION ACTIVITY

Have students research the average fuel costs per gallon in 2007 and in 2012 Have students use the data to create a new graph representing the distance each car could travel for a given amount of money (up to the cost of a typical full tank) Ask students to describe the aspects of their graphs

QUESTIONING STRATEGIESWhy must restrictions be placed on the domain The tank only holds at most 16

gallons of gas and at least 0 gallons of gas A graph

with a negative number of gallons of gas or more

than 16 gallons of gas would not make sense for

this situation

Why does the domain contain all of the points in the interval and not just the integer

values The amount of gas used is continuous

There is a distance traveled for any value of g in

the domain

INTEGRATE MATHEMATICAL PROCESSESFocus on CommunicationEncourage students to relate the ranges that they wrote for the difference functions to their graphs Have them determine whether the values in the range make sense in the real-world situation Then have students explain whether it makes sense that as the number of gallons used increases the difference in miles traveled by the two cars also increases

Scoring Rubric2 points Student correctly solves the problem and explains hisher reasoning1 point Student shows good understanding of the problem but does not fully solve or explain hisher reasoning0 points Student does not demonstrate understanding of the problem

Domain Range and End Behavior 16

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Page 2: CorrectionKey=TX-A CorrectionKey=TX-B LESSON 1 . 1 …€¦ ·  · 2017-01-05A2.7.1 Write the domain and range of a function in interval notation, inequalities, and set notation

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0 42

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-2 -1 0 54321-3-5 -4

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B Complete the table by writing the infinite interval shown on each number line as an inequality using set notation and using interval notation

Infinite Interval 1 2 3 4 50-5 -4 -3 -2 -1 1 2 3 4 50-5 -4 -3 -2 -1

Inequality

Set Notation

Interval Notation

Reflect

1 Consider the interval shown on the number line

a Represent the interval using interval notation

b What numbers are in this interval

2 What do the intervals [0 5] [0 5) and (0 5) have in common What makes them different

3 Discussion The symbol cup represents the union of two sets What do you think the notation (-infin 0) cup (0 + infin) represents

Explain 1 Identifying a Functionrsquos Domain Range and End Behavior from its Graph

Recall that the domain of a function f is the set of input values x and the range is the set of output values ƒ(x) The end behavior of a function describes what happens to the ƒ(x)-values as the x-values either increase without bound (approach positive infinity) or decrease without bound (approach negative infinity) For instance consider the graph of a linear function shown From the graph you can make the following observations

All three intervals contain all the numbers between 0 and 5 The interval [0 5] also

includes the endpoints 0 and 5 the interval [0 5) includes only the endpoint 0 and the

interval (0 5) does not contain either endpoint

All real numbers except 0

(minusinfin +infin)

All real numbers

x le 2

x|x le 2

(minusinfin 2]

x gt 2

x|x gt 2

(2 +infin)

Module 1 6 Lesson 1

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A2_MTXESE353930_U1M01L1indd 6 22214 304 AM

Integrate Mathematical ProcessesThis lesson provides an opportunity to address Mathematical Process TEKS A21D which calls for students to ldquocommunicate mathematical ideas reasoning and their implications using multiple representations including symbols diagrams graphs and language as appropriaterdquo Students learn to describe intervals using inequalities set notation and interval notation They also learn how to use mathematical notation to describe the end behavior of a function

EXPLORE Representing an Interval on a Number Line

INTEGRATE TECHNOLOGYStudents have the option of completing the activity either in the book or online

INTEGRATE MATHEMATICAL PROCESSESFocus on ModelingDraw studentsrsquo attention to the use of braces parentheses and brackets in the various representations Make sure students can use the symbols correctly and can explain the significance of the symbols in each type of notation

EXPLAIN 1 Identifying a Functionrsquos Domain Range and End Behavior from its Graph

AVOID COMMON ERRORSSome students may incorrectly identify the end behavior of a function that increases over the interval (-infin 0) as ldquoAs x rarr -infin ƒ (x) rarr infinrsquorsquo Help students to see that for this part of the description they must consider the behavior of the function as the values of x decrease (the behavior of the graph as observed from right to left) and not whether the function itself is an increasing or decreasing functionPROFESSIONAL DEVELOPMENT

Domain Range and End Behavior 6

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Statement of End Behavior Symbolic Form of Statement

As the x-values increase without bound the f(x)-values also increase without bound

As x rarr +infin f(x) rarr +infin

As the x-values decrease without bound the f(x)-values also decrease without bound

As x rarr -infin f(x) rarr -infin

Example 1 Write the domain and the range of the function as an inequality using set notation and using interval notation Also describe the end behavior of the function

The graph of the quadratic function f(x) = x2 is shown

Domain

Inequality minusinfin lt x lt +infin

Set notation x| minusinfin lt x lt +infin

Interval notation (minusinfin +infin)

Range End behavior

Inequality y ge 0 As x rarr +infin f(x) rarr +infin

Set notation y|y ge 0 As x rarr minusinfin f(x) rarr +infin

Interval notation [0 +infin)

The graph of the exponential function ƒ(x) = 2 x is shown

Domain

Inequality

Set notation

Interval notation

Range

Inequality

Set notation

Interval notation

End behavior

As x rarr +infin

As x rarr +infin

minusinfin lt x lt +infin

x| minusinfin lt x lt +infin

(minusinfin +infin)

y gt 0

y|y gt 0

(0 +infin)

f(x) rarr +infin

f(x) rarr 0

Module 1 7 Lesson 1

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A2_MTXESE353930_U1M01L1indd 7 22214 304 AM

COLLABORATIVE LEARNING

Peer-to-Peer ActivityHave students work in pairs to draw the graph of a linear function with a restricted domain and keep the graph hidden from their partner Have students describe the functionrsquos domain and range using one of the notation forms from the lesson then exchange descriptions and try to draw each otherrsquos graph Have students compare their graphs (which may differ) and discuss the results

QUESTIONING STRATEGIESIs it possible that a linear function with the domain all real numbers could have a range

that is not all real numbers Explain Yes the

function could be a constant function such as

f (x) = 2 The domain is all real numbers but the

range is 2

7 Lesson 1 1

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-2

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0 42

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-2-4

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0 42

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-2

copy H

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Reflect

4 Why is the end behavior of a quadratic function different from the end behavior of a linear function

5 In Part B the ƒ(x)-values decrease as the x-values decrease So why canrsquot you say that f(x) rarr minusinfin as x rarr minusinfin

Your Turn

Write the domain and the range of the function as an inequality using set notation and using interval notation Also describe the end behavior of the function

6 The graph of the quadratic function ƒ(x) = minusx2 is shown

Explain 2 Graphing a Linear Function on a Restricted Domain

Unless otherwise stated a function is assumed to have a domain consisting of all real numbers for which the function is defined Many functionsmdashsuch as linear quadratic and exponential functionsmdashare defined for all real numbers so their domain when written in interval notation is (-infin +infin) Another way to write the set of real numbers is ℝ

Sometimes a function may have a restricted domain If the rule for a function and its restricted domain are given you can draw its graph and then identify its range

Example 2 For the given function and domain draw the graph and identify the range using the same notation as the given domain

ƒ(x) = 3 __ 4 x +2 with domain [-4 4]

Since ƒ(x) = 3 __ 4 x +2 is a linear function the graph is a line segment with endpoints at (-4 ƒ(-4)) or (-4 -1) and (4 ƒ(4)) or (4 5) The endpoints are included in the graph

The range is [-1 5]

Unlike the graph of a linear function the graph of a quadratic function has a turning point

(the vertex) which changes the direction of the graph

The f(x)-values do not decrease without bound They instead approach 0

Domain minusinfin lt x lt +infin x| minusinfin lt x lt +infin (minusinfin +infin)

Range y| y le0 (minusinfin 0]

End behavior As x rarr +infin f(x) rarr -infin As x rarr -infin f(x) rarr -infin

Module 1 8 Lesson 1

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A2_MTXESE353930_U1M01L1indd 8 21415 954 PM

EXPLAIN 2 Graphing a Linear Function on a Restricted Domain

INTEGRATE MATHEMATICAL PROCESSESFocus on Math ConnectionsRemind students that the graph of a function represents the set of ordered pairs produced by the function Help them to see that when they are using a graph to identify the range of a function they are to identify the y-values of those ordered pairs

DIFFERENTIATE INSTRUCTION

Cognitive StrategiesIf students have a difficult time consistently identifying the domain and range of functions encourage them to use the phrase depends on instead of is a function of For example ldquoThe distance traveled by a car depends on the amount of gas in the tankrdquo Help them to see that the elements of the range ldquodepend onrdquo the elements of the domain

Domain Range and End Behavior 8

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0 42

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0 2

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4

2

y

0 42

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-2-4

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Bƒ(x) = -x - 2 with domain x|x gt -3

Since ƒ(x) = -x -2 is a linear function the graph is a ray with its endpoint at (-3 ƒ(-3)) or

The endpoint included in the graph

The range is

Reflect

7 In Part A how does the graph change if the domain is (-4 4) instead of [-4 4]

8 In Part B what is the end behavior as x increases without bound Why canrsquot you talk about the end behavior as x decreases without bound

Your Turn

For the given function and domain draw the graph and identify the range using the same notation as the given domain

9 ƒ(x) = - 1 _ 2 x + 2 with domain -6 le x lt 2 10 f(x) = 2 _ 3 x -1 with domain (minusinfin 3]

(-3 1)

is not

y|y lt 1

The graph no longer includes the endpoints of the segment

As x rarr +infin f(x) rarr -infin Because the domain does not include values of x that are less

than or equal to -3 the values of x cannot decrease without bound

The range is 1 lt y le 5 The range is (minusinfin 1]

Module 1 9 Lesson 1

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A2_MTXESE353930_U1M01L1indd 9 11415 241 AM

LANGUAGE SUPPORT

Connect VocabularyHave students work in pairs Instruct one student to verbally describe the domain range and end behavior of a function without using those three terms Have the other student fill in a graphic organizer with boxes titled Domain Range and End behavior and write in the appropriate values under each box Have students switch roles and repeat the exercise using a different function

QUESTIONING STRATEGIESIf a linear function has a restricted domain must the range consist of a finite number of

elements Explain No If the domain is restricted to

an interval (or intervals) as opposed to a finite

number of elements the range could consist of

infinitely many values For example the range of

the function f (x) = 3x with domain ⎡ ⎣ 0 5 ⎤ ⎦ is ⎡ ⎣ 0 15 ⎤ ⎦

an interval containing infinitely many numbers

If the domain of a linear function consists of n elements how many elements would there be

in the range Explain One if the function is a

constant function or n if it is not In a non-constant

linear function each element of the domain is

paired with a different element of the range

9 Lesson 1 1

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0

1

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Time (min)

Dis

tanc

e (m

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d

t

40302010

0

2

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8

1

3

5

7

Time (h)

Hei

ght (

in)

h

t

4321 8765

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pany bull Im

age C

redits copy

Bounce

Up

perC

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esGetty Im

ages

Explain 3 Modeling with a Linear FunctionRecall that when a real-world situation involves a constant rate of change a linear function is a reasonable model for the situation The situation may require restricting the functionrsquos domain

Example 3 Write a function that models the given situation Determine a domain from the situation graph the function using that domain and identify the range

Joyce jogs at a rate of 1 mile every 10 minutes for a total of 40 minutes (Use inequalities for the domain and range of the function that models this situation)

Joycersquos jogging rate is 01 mimin Her jogging distance d (in miles) at any time t (in minutes) is modeled by d(t) = 01t Since she jogs for 40 minutes the domain is restricted to the interval 0 le t le 40

The range is 0 le d le 4

A candle 6 inches high burns at a rate of 1 inch every 2 hours for 5 hours (Use interval notation for the domain and range of the function that models this situation)

The candlersquos burning rate is inh The candlersquos height h (in inches) at any time t (in hours) is modeled by h(t) =

Since the candle burns for 5 hours the domain is restricted to the

interval ⎡

⎢ ⎣ 0

⎥ ⎦

The range is

-05

6 - 05t

5

[35 6]

Module 1 10 Lesson 1

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A2_MTXESE353930_U1M01L1indd 10 11215 430 PM

EXPLAIN 3 Modeling with a Linear Function

AVOID COMMON ERRORSSome students may erroneously identify the domain of a function that represents a real-world situation as an interval when in fact the domain consists only of specific numbers within the interval such as integers or multiples of a particular rational number Help students to avoid this error by encouraging them to ask themselves whether any number within the interval could be a realistic input value for the situation described by the function

INTEGRATE MATHEMATICAL PROCESSESFocus on ReasoningEncourage students to check their work by considering the reasonableness of the range of the function Have them evaluate whether the values in the range seem realistic for the given situation

Domain Range and End Behavior 10

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Reflect

11 In Part A suppose Joyce jogs for only 30 minutes

A How does the domain change

B How does the graph change

C How does the range change

Your Turn

12 While standing on a moving walkway at an airport you are carried forward 25 feet every 15 seconds for 1 minute Write a function that models this situation Determine the domain from the situation graph the function and identify the range Use set notation for the domain and range

Elaborate

13 If a and b are real numbers such that a lt b use interval notation to write four different intervals having a and b as endpoints Describe what numbers each interval includes

14 What impact does restricting the domain of a linear function have on the graph of the function

15 Essential Question Check-In How does slope determine the end behavior of a linear function with an unrestricted domain

The domain is 0 le t le 30 instead of 0 le t le 40

The graphrsquos right endpoint is (30 3) instead of (40 4)

The range is 0 le d le 3 instead of 0 le d le 4

The walkwayrsquos rate of motion is 5 __ 3 fts The distance d (in feet)

you travel at any time t (in seconds) is modeled by d(t) = 5 __ 3 t

Domain t| 0 le t le 60 range d| 0 le d le 100

[a b] This interval includes all real numbers between a and b including both a and b

[a b) This interval includes all real numbers between a and b including a but not b

(a b] This interval includes all real numbers between a and b including b but not a

(a b) This interval includes all real numbers between a and b but does not include a or b

If slope is positive the f(x)-values increase without bound as the x-values increase without

bound and the f(x)-values decrease without bound as the x-values decrease without bound

If the slope is negative the end behavior reverses The f(x)-values decrease without bound

as the x-values increase without bound and the f(x)-values increase without bound as the

x-values decrease without bound

If the domain is bounded at both ends the graph of the linear function is a line segment

rather than a line If the domain is bounded at only one end the graph of the linear function

is a ray rather than a line

Module 1 11 Lesson 1

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A2_MTXESE353930_U1M01L1indd 11 11415 241 AM

ELABORATE INTEGRATE MATHEMATICAL PROCESSESFocus on CommunicationDiscuss different strategies for determining the range of a function from a graph of the function Have students describe methods they use and illustrate their methods using graphs of different types of functions including those with restricted domains

QUESTIONING STRATEGIESIs it possible that a real-world situation can be modeled by a function whose domain consists

of both positive and negative real numbers If no explain why not If yes give an example Yes

Possible example a function that describes the

relationship between air temperature in degrees

Fahrenheit and dew point at a given level of

humidity The domain consists of all possible air

temperatures in degrees Fahrenheit

SUMMARIZE THE LESSONHow do you identify and represent the domain range and end behavior of a

function To identify the domain find the values of

x for which the function is defined To find the

range find the values of f (x) for each value of x in

the domain There are different ways of

representing the domain and range including using

inequalities set notation and interval notation To

find the end-behavior consider what happens to

the values of the range as the values of the domain

increase or decrease without bound

11 Lesson 1 1

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bull Online Homeworkbull Hints and Helpbull Extra Practice

1 Write the interval shown on the number line as an inequality using set notation and using interval notation

2 Write the interval (5 100] as an inequality and using set notation

3 Write the interval -25 le x lt 30 using set notation and interval notation

4 Write the interval x| -3 lt x lt 5 as an inequality and using interval notation

Write the domain and the range of the function as an inequality using set notation and using interval notation Also describe the end behavior of the function or explain why there is no end behavior

5 The graph of the quadratic functionf (x) = x 2 + 2 is shown

6 The graph of the exponential function f (x) = 3 x is shown

Evaluate Homework and Practice

x ge 5 x|x ge 5 [5 +infin)

x| -25 le x lt 30 [-25 30)

5 lt x le 100 x|5 lt x le 100

-3 lt x lt 5 (-3 5)

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range 2 le y lt +infin y⎪ 2 le y lt +infin ⎡ ⎣ 2 +infin)End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr +infin

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range 0 lt y lt +infin y⎪ 0 lt y lt +infin (0 +infin)End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr 0

Module 1 12 Lesson 1

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A2_MTXESE353930_U1M01L1indd 12 22214 304 AMExercise Depth of Knowledge (DOK) Mathematical Processes

1ndash8 1 Recall of Information 1F Analyze relationships

9ndash10 1 Recall of Information 1E Create and use representations

11 1 Recall of Information 1D Multiple representations

12 2 SkillsConcepts 1A Everyday life

13 2 SkillsConcepts 1G Explain and justify arguments

14 3 Strategic Thinking 1D Multiple representations

EVALUATE

ASSIGNMENT GUIDE

Concepts and Skills Practice

ExploreRepresenting an Interval on a Number Line

Exercise 1ndash4

Example 1Identifying a Functionrsquos Domain Range and End Behavior from its Graph

Exercises 5ndash8

Example 2Graphing a Linear Function on a Restricted Domain

Exercises 9ndash10

Example 3Modeling with a Linear Function

Exercises 11ndash12

VISUAL CUESSome students may benefit from labeling the endpoints of an interval as included or not included as indicated by the closed circle or open circle on the graph They will then be sure to use the appropriate symbols when describing the interval using the different types of notation

CONNECT VOCABULARY Relate end behavior to the shape of the graph of different functions Have students use words to describe the end behavior of each function by looking at the graph For example a function ƒ (x) appears to rise for positive x-values and fall for negative x-values

Domain Range and End Behavior 12

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7 The graph of the linear function g (x) = 2x - 2 is shown

8 The graph of a function is shown

For the given function and domain draw the graph and identify the range using the same notation as the given domain

9 f(x) = minusx + 5 with domain [minus3 2] 10 f(x) = 3 _ 2 x + 1 with domain x |x gt minus 2

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range minusinfin lt y lt +infin y⎪ minusinfin lt y lt +infin (minusinfin +infin) End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr -infin

Domain minus4 le x le 4 x⎪ minus4 le x le 4 [minus4 4]

Range 0 le y le 4 y⎪ 0 le y le 4 [0 4]

There is no end behavior because the domain is bounded at both ends

Since f (x) = -x + 5 is a linear

function the graph is a line

segment with endpoints at

(-3 f (-3) ) or (minus3 8) and

(2 f(2)) or (2 3) The endpoints

are included in the graph

The range is [3 8]

Since f (x) = 3 _ 2

x + 1 is a linear

function the graph is a ray with

its endpoint at (-2 f (-2) )

or (minus2 minus2) The endpoint is not

included in the graph

The range is y⎪ y gt - 2

Module 1 13 Lesson 1

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A2_MTXESE353930_U1M01L1indd 13 11415 241 AMExercise Depth of Knowledge (DOK) Mathematical Processes

15 2 SkillsConcepts 1E Create and use representations

MULTIPLE REPRESENTATIONSWhen analyzing the graph of a function students may find it easier to first describe the end behavior of the function in words They then can translate their verbal descriptions into algebraic notation making sure that the symbols accurately reflect their descriptions

KINESTHETIC EXPERIENCETo help students correctly identify end behavior suggest that they use a finger to trace along the graph of a function moving first from left to right as x rarr infin and then from right to left as x rarr -infin Help them to match their observations of the behavior of the graph to its correct description and notation

13 Lesson 1 1

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Write a function that models the given situation Determine the domain from the situation graph the function using that domain and identify the range

11 A bicyclist travels at a constant speed of 12 miles per hour for a total of 45 minutes (Use set notation for the domain and range of the function that models this situation)

12 An elevator in a tall building starts at a floor of the building that is 90 meters above the ground The elevator descends 2 meters every 05 second for 6 seconds (Use an inequality for the domain and range of the function that models this situation)

HOT Focus on Higher Order Thinking

13 Explain the Error Cameron sells tickets at a movie theater On Friday night she worked from 4 pm to 10 pm and sold about 25 tickets every hour Cameron says that the number of tickets n she has sold at any time t (in hours) can be modeled by the function n(t) = 25t where the domain is 0 le t le 1 and the range is 0 le n le 25 Is Cameronrsquos function along with the domain and range correct Explain

The bicyclistrsquos speed is 12 mih The distance traveled

d (in miles) at any time t (in hours) is modeled by

d(t) = 12t Since the bicyclist travels for 45 minutes

or 075 hour the domain is restricted to the interval

t⎪0 le t le 075

The range is d⎪0 le d le 9

The elevatorrsquos rate of motion is -4 ms The elevatorrsquos

height h (in meters) at any time t (in seconds) is modeled by

h(t) = 90 - 4t Since the elevator descends for 6 seconds

the domain is restricted to the interval 0 le t le 6

The range is 66 le h le 90

Cameronrsquos function is correct but the domain and range are incorrect Cameron worked for a total of 6 hours so the domain of the function should be 0 le t le 6 After 6 hours Cameron has sold 25 times 6 = 150 tickets So the range of the function should be 0 le n le 150

Module 1 14 Lesson 1

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A2_MTXESE353930_U1M01L1indd 14 11415 241 AM

QUESTIONING STRATEGIESWhen is the graph of a linear function with a restricted domain a line segment When is it a

ray It is a line segment when the domain is a

closed interval It is a ray when the domain is

restricted to real numbers greater than or equal to a

number or less than or equal to a number

AVOID COMMON ERRORSWhen attempting to model a real-world situation students sometimes confuse the dependent and independent variables thus reversing the domain and range Help them to understand that the domain consists of the values represented by the independent variable and that the range values are a function of the values of the domain

Domain Range and End Behavior 14

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400200 800 1000600

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14 Multi-Step The graph of the cubic function ƒ(x) = x 3 is shown

a What are the domain range and end behavior of the function (Write the domain and range as an inequality using set notation and using interval notation)

b How is the range of the function affected if the domain is restricted to [-4 4] (Write the range as an inequality using set notation and using interval notation)

c Graph the function with the restricted domain

15 Represent Real-World Situations The John James Audubon Bridge is a cable-stayed bridge in Louisiana that opened in 2011 The height from the bridge deck to the top of the tower where a particular cable is anchored is about 500 feet and the length of that cable is about 1200 feet Draw the cable on a coordinate plane letting the x-axis represent the bridge deck and the y-axis represent the tower (Only use positive values of x and y) Write a linear function whose graph models the cable Identify the domain and range writing each as an inequality using set notation and using interval notation

a Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range minusinfin lt y lt +infin y⎪ minusinfin lt y lt +infin (minusinfin +infin) End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr -infin

b Restricted range -64 le y le 64 y⎪ minus64 le y le +64 [-64 64]

c

Since the cable the bridge deck and the

tower form a right triangle find the length

of the leg that lies on the x-axis by using the

Pythagorean Theorem

a 2 + b 2 = c 2

500 2 + b 2 = 1200 2

b asymp 109 1

slope m = 500 - 0 _ 0 - 1091

= 500 _ -1091 asymp -046

The y-intercept is 500

So the linear function is y = -046x + 500

Domain 0 le x le 1091 x⎪0 le x le 1091 [0 1091]

Range 0 le y le 500 y⎪0 le y le 500 [0 500]

Module 1 15 Lesson 1

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A2_MTXESE353930_U1M01L1indd 15 11415 241 AM

PEERTOPEER DISCUSSIONIs it possible that a linear function with the domain all real numbers could have a range that is not all real numbers Explain Yes the function could be a

constant function such as f (x) = 2 The domain is

all real numbers but the range is 2

You may want to have students work on the modeling questions in pairs thus providing them with an opportunity to discuss each situation with a partner and decide how to best model the situation using a function

JOURNALHave students describe how to identify the domain and range of a function given its graph or given the situation it models

15 Lesson 1 1

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0

100

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400450500550

50

150

250

350

Gas used (gal)

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avel

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161284

20122007

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The fuel efficiency for a 2007 passenger car was 312 migal For the same model of car the fuel efficiency increased to 356 migal in 2012 The gas tank for this car holds 16 gallons of gas

a Write and graph a linear function that models the distance that each car can travel for a given amount of gas (up to one tankful)

b Write the domain and range of each function using interval notation

c Write and simplify a function ƒ (g) that represents the difference in the distance that the 2012 car can travel and the distance that the 2007 car can travel on the same amount of gas Interpret this function using the graphs of the functions from part a Also find and interpret ƒ (16)

d Write the domain and range of the difference function using set notation

Lesson Performance Task

a For both cars let g be the amount of gas (in gallons) that each car uses and let d be the distance (in miles) that each car travels For the 2007 car the linear model is d 2007 (g) = 312g For the 2012 car the linear model is d 2012 (g) = 356g

b The domain for the 2007 model is [0 16] and the range is [0 4992] The domain for the 2012 model is [0 16] and the range is [0 5696]

c The difference function is f(g) = d 2012 (g) minus d 2007 (g) = 356g minus 312g = 44g This function gives the vertical distance between the graphs of d 2012 (g) and d 2007 (g) For instance when g = 16 the vertical distance between the graphs is f(16) = 44 16 = 704 which means the 2012 car can travel 704 miles farther on a tankful of gas than the 2007 car

d The domain is g⎪0 le g le 16 and the range is f(g)⎪0 le f(g) le 704

Module 1 16 Lesson 1

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A2_MTXESE353930_U1M01L1indd 16 22214 319 AM

EXTENSION ACTIVITY

Have students research the average fuel costs per gallon in 2007 and in 2012 Have students use the data to create a new graph representing the distance each car could travel for a given amount of money (up to the cost of a typical full tank) Ask students to describe the aspects of their graphs

QUESTIONING STRATEGIESWhy must restrictions be placed on the domain The tank only holds at most 16

gallons of gas and at least 0 gallons of gas A graph

with a negative number of gallons of gas or more

than 16 gallons of gas would not make sense for

this situation

Why does the domain contain all of the points in the interval and not just the integer

values The amount of gas used is continuous

There is a distance traveled for any value of g in

the domain

INTEGRATE MATHEMATICAL PROCESSESFocus on CommunicationEncourage students to relate the ranges that they wrote for the difference functions to their graphs Have them determine whether the values in the range make sense in the real-world situation Then have students explain whether it makes sense that as the number of gallons used increases the difference in miles traveled by the two cars also increases

Scoring Rubric2 points Student correctly solves the problem and explains hisher reasoning1 point Student shows good understanding of the problem but does not fully solve or explain hisher reasoning0 points Student does not demonstrate understanding of the problem

Domain Range and End Behavior 16

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Page 3: CorrectionKey=TX-A CorrectionKey=TX-B LESSON 1 . 1 …€¦ ·  · 2017-01-05A2.7.1 Write the domain and range of a function in interval notation, inequalities, and set notation

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Statement of End Behavior Symbolic Form of Statement

As the x-values increase without bound the f(x)-values also increase without bound

As x rarr +infin f(x) rarr +infin

As the x-values decrease without bound the f(x)-values also decrease without bound

As x rarr -infin f(x) rarr -infin

Example 1 Write the domain and the range of the function as an inequality using set notation and using interval notation Also describe the end behavior of the function

The graph of the quadratic function f(x) = x2 is shown

Domain

Inequality minusinfin lt x lt +infin

Set notation x| minusinfin lt x lt +infin

Interval notation (minusinfin +infin)

Range End behavior

Inequality y ge 0 As x rarr +infin f(x) rarr +infin

Set notation y|y ge 0 As x rarr minusinfin f(x) rarr +infin

Interval notation [0 +infin)

The graph of the exponential function ƒ(x) = 2 x is shown

Domain

Inequality

Set notation

Interval notation

Range

Inequality

Set notation

Interval notation

End behavior

As x rarr +infin

As x rarr +infin

minusinfin lt x lt +infin

x| minusinfin lt x lt +infin

(minusinfin +infin)

y gt 0

y|y gt 0

(0 +infin)

f(x) rarr +infin

f(x) rarr 0

Module 1 7 Lesson 1

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A2_MTXESE353930_U1M01L1indd 7 22214 304 AM

COLLABORATIVE LEARNING

Peer-to-Peer ActivityHave students work in pairs to draw the graph of a linear function with a restricted domain and keep the graph hidden from their partner Have students describe the functionrsquos domain and range using one of the notation forms from the lesson then exchange descriptions and try to draw each otherrsquos graph Have students compare their graphs (which may differ) and discuss the results

QUESTIONING STRATEGIESIs it possible that a linear function with the domain all real numbers could have a range

that is not all real numbers Explain Yes the

function could be a constant function such as

f (x) = 2 The domain is all real numbers but the

range is 2

7 Lesson 1 1

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Reflect

4 Why is the end behavior of a quadratic function different from the end behavior of a linear function

5 In Part B the ƒ(x)-values decrease as the x-values decrease So why canrsquot you say that f(x) rarr minusinfin as x rarr minusinfin

Your Turn

Write the domain and the range of the function as an inequality using set notation and using interval notation Also describe the end behavior of the function

6 The graph of the quadratic function ƒ(x) = minusx2 is shown

Explain 2 Graphing a Linear Function on a Restricted Domain

Unless otherwise stated a function is assumed to have a domain consisting of all real numbers for which the function is defined Many functionsmdashsuch as linear quadratic and exponential functionsmdashare defined for all real numbers so their domain when written in interval notation is (-infin +infin) Another way to write the set of real numbers is ℝ

Sometimes a function may have a restricted domain If the rule for a function and its restricted domain are given you can draw its graph and then identify its range

Example 2 For the given function and domain draw the graph and identify the range using the same notation as the given domain

ƒ(x) = 3 __ 4 x +2 with domain [-4 4]

Since ƒ(x) = 3 __ 4 x +2 is a linear function the graph is a line segment with endpoints at (-4 ƒ(-4)) or (-4 -1) and (4 ƒ(4)) or (4 5) The endpoints are included in the graph

The range is [-1 5]

Unlike the graph of a linear function the graph of a quadratic function has a turning point

(the vertex) which changes the direction of the graph

The f(x)-values do not decrease without bound They instead approach 0

Domain minusinfin lt x lt +infin x| minusinfin lt x lt +infin (minusinfin +infin)

Range y| y le0 (minusinfin 0]

End behavior As x rarr +infin f(x) rarr -infin As x rarr -infin f(x) rarr -infin

Module 1 8 Lesson 1

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A2_MTXESE353930_U1M01L1indd 8 21415 954 PM

EXPLAIN 2 Graphing a Linear Function on a Restricted Domain

INTEGRATE MATHEMATICAL PROCESSESFocus on Math ConnectionsRemind students that the graph of a function represents the set of ordered pairs produced by the function Help them to see that when they are using a graph to identify the range of a function they are to identify the y-values of those ordered pairs

DIFFERENTIATE INSTRUCTION

Cognitive StrategiesIf students have a difficult time consistently identifying the domain and range of functions encourage them to use the phrase depends on instead of is a function of For example ldquoThe distance traveled by a car depends on the amount of gas in the tankrdquo Help them to see that the elements of the range ldquodepend onrdquo the elements of the domain

Domain Range and End Behavior 8

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Bƒ(x) = -x - 2 with domain x|x gt -3

Since ƒ(x) = -x -2 is a linear function the graph is a ray with its endpoint at (-3 ƒ(-3)) or

The endpoint included in the graph

The range is

Reflect

7 In Part A how does the graph change if the domain is (-4 4) instead of [-4 4]

8 In Part B what is the end behavior as x increases without bound Why canrsquot you talk about the end behavior as x decreases without bound

Your Turn

For the given function and domain draw the graph and identify the range using the same notation as the given domain

9 ƒ(x) = - 1 _ 2 x + 2 with domain -6 le x lt 2 10 f(x) = 2 _ 3 x -1 with domain (minusinfin 3]

(-3 1)

is not

y|y lt 1

The graph no longer includes the endpoints of the segment

As x rarr +infin f(x) rarr -infin Because the domain does not include values of x that are less

than or equal to -3 the values of x cannot decrease without bound

The range is 1 lt y le 5 The range is (minusinfin 1]

Module 1 9 Lesson 1

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A2_MTXESE353930_U1M01L1indd 9 11415 241 AM

LANGUAGE SUPPORT

Connect VocabularyHave students work in pairs Instruct one student to verbally describe the domain range and end behavior of a function without using those three terms Have the other student fill in a graphic organizer with boxes titled Domain Range and End behavior and write in the appropriate values under each box Have students switch roles and repeat the exercise using a different function

QUESTIONING STRATEGIESIf a linear function has a restricted domain must the range consist of a finite number of

elements Explain No If the domain is restricted to

an interval (or intervals) as opposed to a finite

number of elements the range could consist of

infinitely many values For example the range of

the function f (x) = 3x with domain ⎡ ⎣ 0 5 ⎤ ⎦ is ⎡ ⎣ 0 15 ⎤ ⎦

an interval containing infinitely many numbers

If the domain of a linear function consists of n elements how many elements would there be

in the range Explain One if the function is a

constant function or n if it is not In a non-constant

linear function each element of the domain is

paired with a different element of the range

9 Lesson 1 1

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1

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3

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Time (min)

Dis

tanc

e (m

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t

40302010

0

2

4

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8

1

3

5

7

Time (h)

Hei

ght (

in)

h

t

4321 8765

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Explain 3 Modeling with a Linear FunctionRecall that when a real-world situation involves a constant rate of change a linear function is a reasonable model for the situation The situation may require restricting the functionrsquos domain

Example 3 Write a function that models the given situation Determine a domain from the situation graph the function using that domain and identify the range

Joyce jogs at a rate of 1 mile every 10 minutes for a total of 40 minutes (Use inequalities for the domain and range of the function that models this situation)

Joycersquos jogging rate is 01 mimin Her jogging distance d (in miles) at any time t (in minutes) is modeled by d(t) = 01t Since she jogs for 40 minutes the domain is restricted to the interval 0 le t le 40

The range is 0 le d le 4

A candle 6 inches high burns at a rate of 1 inch every 2 hours for 5 hours (Use interval notation for the domain and range of the function that models this situation)

The candlersquos burning rate is inh The candlersquos height h (in inches) at any time t (in hours) is modeled by h(t) =

Since the candle burns for 5 hours the domain is restricted to the

interval ⎡

⎢ ⎣ 0

⎥ ⎦

The range is

-05

6 - 05t

5

[35 6]

Module 1 10 Lesson 1

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A2_MTXESE353930_U1M01L1indd 10 11215 430 PM

EXPLAIN 3 Modeling with a Linear Function

AVOID COMMON ERRORSSome students may erroneously identify the domain of a function that represents a real-world situation as an interval when in fact the domain consists only of specific numbers within the interval such as integers or multiples of a particular rational number Help students to avoid this error by encouraging them to ask themselves whether any number within the interval could be a realistic input value for the situation described by the function

INTEGRATE MATHEMATICAL PROCESSESFocus on ReasoningEncourage students to check their work by considering the reasonableness of the range of the function Have them evaluate whether the values in the range seem realistic for the given situation

Domain Range and End Behavior 10

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Reflect

11 In Part A suppose Joyce jogs for only 30 minutes

A How does the domain change

B How does the graph change

C How does the range change

Your Turn

12 While standing on a moving walkway at an airport you are carried forward 25 feet every 15 seconds for 1 minute Write a function that models this situation Determine the domain from the situation graph the function and identify the range Use set notation for the domain and range

Elaborate

13 If a and b are real numbers such that a lt b use interval notation to write four different intervals having a and b as endpoints Describe what numbers each interval includes

14 What impact does restricting the domain of a linear function have on the graph of the function

15 Essential Question Check-In How does slope determine the end behavior of a linear function with an unrestricted domain

The domain is 0 le t le 30 instead of 0 le t le 40

The graphrsquos right endpoint is (30 3) instead of (40 4)

The range is 0 le d le 3 instead of 0 le d le 4

The walkwayrsquos rate of motion is 5 __ 3 fts The distance d (in feet)

you travel at any time t (in seconds) is modeled by d(t) = 5 __ 3 t

Domain t| 0 le t le 60 range d| 0 le d le 100

[a b] This interval includes all real numbers between a and b including both a and b

[a b) This interval includes all real numbers between a and b including a but not b

(a b] This interval includes all real numbers between a and b including b but not a

(a b) This interval includes all real numbers between a and b but does not include a or b

If slope is positive the f(x)-values increase without bound as the x-values increase without

bound and the f(x)-values decrease without bound as the x-values decrease without bound

If the slope is negative the end behavior reverses The f(x)-values decrease without bound

as the x-values increase without bound and the f(x)-values increase without bound as the

x-values decrease without bound

If the domain is bounded at both ends the graph of the linear function is a line segment

rather than a line If the domain is bounded at only one end the graph of the linear function

is a ray rather than a line

Module 1 11 Lesson 1

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A2_MTXESE353930_U1M01L1indd 11 11415 241 AM

ELABORATE INTEGRATE MATHEMATICAL PROCESSESFocus on CommunicationDiscuss different strategies for determining the range of a function from a graph of the function Have students describe methods they use and illustrate their methods using graphs of different types of functions including those with restricted domains

QUESTIONING STRATEGIESIs it possible that a real-world situation can be modeled by a function whose domain consists

of both positive and negative real numbers If no explain why not If yes give an example Yes

Possible example a function that describes the

relationship between air temperature in degrees

Fahrenheit and dew point at a given level of

humidity The domain consists of all possible air

temperatures in degrees Fahrenheit

SUMMARIZE THE LESSONHow do you identify and represent the domain range and end behavior of a

function To identify the domain find the values of

x for which the function is defined To find the

range find the values of f (x) for each value of x in

the domain There are different ways of

representing the domain and range including using

inequalities set notation and interval notation To

find the end-behavior consider what happens to

the values of the range as the values of the domain

increase or decrease without bound

11 Lesson 1 1

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bull Online Homeworkbull Hints and Helpbull Extra Practice

1 Write the interval shown on the number line as an inequality using set notation and using interval notation

2 Write the interval (5 100] as an inequality and using set notation

3 Write the interval -25 le x lt 30 using set notation and interval notation

4 Write the interval x| -3 lt x lt 5 as an inequality and using interval notation

Write the domain and the range of the function as an inequality using set notation and using interval notation Also describe the end behavior of the function or explain why there is no end behavior

5 The graph of the quadratic functionf (x) = x 2 + 2 is shown

6 The graph of the exponential function f (x) = 3 x is shown

Evaluate Homework and Practice

x ge 5 x|x ge 5 [5 +infin)

x| -25 le x lt 30 [-25 30)

5 lt x le 100 x|5 lt x le 100

-3 lt x lt 5 (-3 5)

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range 2 le y lt +infin y⎪ 2 le y lt +infin ⎡ ⎣ 2 +infin)End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr +infin

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range 0 lt y lt +infin y⎪ 0 lt y lt +infin (0 +infin)End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr 0

Module 1 12 Lesson 1

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A2_MTXESE353930_U1M01L1indd 12 22214 304 AMExercise Depth of Knowledge (DOK) Mathematical Processes

1ndash8 1 Recall of Information 1F Analyze relationships

9ndash10 1 Recall of Information 1E Create and use representations

11 1 Recall of Information 1D Multiple representations

12 2 SkillsConcepts 1A Everyday life

13 2 SkillsConcepts 1G Explain and justify arguments

14 3 Strategic Thinking 1D Multiple representations

EVALUATE

ASSIGNMENT GUIDE

Concepts and Skills Practice

ExploreRepresenting an Interval on a Number Line

Exercise 1ndash4

Example 1Identifying a Functionrsquos Domain Range and End Behavior from its Graph

Exercises 5ndash8

Example 2Graphing a Linear Function on a Restricted Domain

Exercises 9ndash10

Example 3Modeling with a Linear Function

Exercises 11ndash12

VISUAL CUESSome students may benefit from labeling the endpoints of an interval as included or not included as indicated by the closed circle or open circle on the graph They will then be sure to use the appropriate symbols when describing the interval using the different types of notation

CONNECT VOCABULARY Relate end behavior to the shape of the graph of different functions Have students use words to describe the end behavior of each function by looking at the graph For example a function ƒ (x) appears to rise for positive x-values and fall for negative x-values

Domain Range and End Behavior 12

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7 The graph of the linear function g (x) = 2x - 2 is shown

8 The graph of a function is shown

For the given function and domain draw the graph and identify the range using the same notation as the given domain

9 f(x) = minusx + 5 with domain [minus3 2] 10 f(x) = 3 _ 2 x + 1 with domain x |x gt minus 2

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range minusinfin lt y lt +infin y⎪ minusinfin lt y lt +infin (minusinfin +infin) End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr -infin

Domain minus4 le x le 4 x⎪ minus4 le x le 4 [minus4 4]

Range 0 le y le 4 y⎪ 0 le y le 4 [0 4]

There is no end behavior because the domain is bounded at both ends

Since f (x) = -x + 5 is a linear

function the graph is a line

segment with endpoints at

(-3 f (-3) ) or (minus3 8) and

(2 f(2)) or (2 3) The endpoints

are included in the graph

The range is [3 8]

Since f (x) = 3 _ 2

x + 1 is a linear

function the graph is a ray with

its endpoint at (-2 f (-2) )

or (minus2 minus2) The endpoint is not

included in the graph

The range is y⎪ y gt - 2

Module 1 13 Lesson 1

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A2_MTXESE353930_U1M01L1indd 13 11415 241 AMExercise Depth of Knowledge (DOK) Mathematical Processes

15 2 SkillsConcepts 1E Create and use representations

MULTIPLE REPRESENTATIONSWhen analyzing the graph of a function students may find it easier to first describe the end behavior of the function in words They then can translate their verbal descriptions into algebraic notation making sure that the symbols accurately reflect their descriptions

KINESTHETIC EXPERIENCETo help students correctly identify end behavior suggest that they use a finger to trace along the graph of a function moving first from left to right as x rarr infin and then from right to left as x rarr -infin Help them to match their observations of the behavior of the graph to its correct description and notation

13 Lesson 1 1

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lamy

Write a function that models the given situation Determine the domain from the situation graph the function using that domain and identify the range

11 A bicyclist travels at a constant speed of 12 miles per hour for a total of 45 minutes (Use set notation for the domain and range of the function that models this situation)

12 An elevator in a tall building starts at a floor of the building that is 90 meters above the ground The elevator descends 2 meters every 05 second for 6 seconds (Use an inequality for the domain and range of the function that models this situation)

HOT Focus on Higher Order Thinking

13 Explain the Error Cameron sells tickets at a movie theater On Friday night she worked from 4 pm to 10 pm and sold about 25 tickets every hour Cameron says that the number of tickets n she has sold at any time t (in hours) can be modeled by the function n(t) = 25t where the domain is 0 le t le 1 and the range is 0 le n le 25 Is Cameronrsquos function along with the domain and range correct Explain

The bicyclistrsquos speed is 12 mih The distance traveled

d (in miles) at any time t (in hours) is modeled by

d(t) = 12t Since the bicyclist travels for 45 minutes

or 075 hour the domain is restricted to the interval

t⎪0 le t le 075

The range is d⎪0 le d le 9

The elevatorrsquos rate of motion is -4 ms The elevatorrsquos

height h (in meters) at any time t (in seconds) is modeled by

h(t) = 90 - 4t Since the elevator descends for 6 seconds

the domain is restricted to the interval 0 le t le 6

The range is 66 le h le 90

Cameronrsquos function is correct but the domain and range are incorrect Cameron worked for a total of 6 hours so the domain of the function should be 0 le t le 6 After 6 hours Cameron has sold 25 times 6 = 150 tickets So the range of the function should be 0 le n le 150

Module 1 14 Lesson 1

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A2_MTXESE353930_U1M01L1indd 14 11415 241 AM

QUESTIONING STRATEGIESWhen is the graph of a linear function with a restricted domain a line segment When is it a

ray It is a line segment when the domain is a

closed interval It is a ray when the domain is

restricted to real numbers greater than or equal to a

number or less than or equal to a number

AVOID COMMON ERRORSWhen attempting to model a real-world situation students sometimes confuse the dependent and independent variables thus reversing the domain and range Help them to understand that the domain consists of the values represented by the independent variable and that the range values are a function of the values of the domain

Domain Range and End Behavior 14

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x2 4-4

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-50

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200

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800

Distance from tower (ft)

Hei

ght a

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deck

(ft)

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x

400200 800 1000600

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14 Multi-Step The graph of the cubic function ƒ(x) = x 3 is shown

a What are the domain range and end behavior of the function (Write the domain and range as an inequality using set notation and using interval notation)

b How is the range of the function affected if the domain is restricted to [-4 4] (Write the range as an inequality using set notation and using interval notation)

c Graph the function with the restricted domain

15 Represent Real-World Situations The John James Audubon Bridge is a cable-stayed bridge in Louisiana that opened in 2011 The height from the bridge deck to the top of the tower where a particular cable is anchored is about 500 feet and the length of that cable is about 1200 feet Draw the cable on a coordinate plane letting the x-axis represent the bridge deck and the y-axis represent the tower (Only use positive values of x and y) Write a linear function whose graph models the cable Identify the domain and range writing each as an inequality using set notation and using interval notation

a Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range minusinfin lt y lt +infin y⎪ minusinfin lt y lt +infin (minusinfin +infin) End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr -infin

b Restricted range -64 le y le 64 y⎪ minus64 le y le +64 [-64 64]

c

Since the cable the bridge deck and the

tower form a right triangle find the length

of the leg that lies on the x-axis by using the

Pythagorean Theorem

a 2 + b 2 = c 2

500 2 + b 2 = 1200 2

b asymp 109 1

slope m = 500 - 0 _ 0 - 1091

= 500 _ -1091 asymp -046

The y-intercept is 500

So the linear function is y = -046x + 500

Domain 0 le x le 1091 x⎪0 le x le 1091 [0 1091]

Range 0 le y le 500 y⎪0 le y le 500 [0 500]

Module 1 15 Lesson 1

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A2_MTXESE353930_U1M01L1indd 15 11415 241 AM

PEERTOPEER DISCUSSIONIs it possible that a linear function with the domain all real numbers could have a range that is not all real numbers Explain Yes the function could be a

constant function such as f (x) = 2 The domain is

all real numbers but the range is 2

You may want to have students work on the modeling questions in pairs thus providing them with an opportunity to discuss each situation with a partner and decide how to best model the situation using a function

JOURNALHave students describe how to identify the domain and range of a function given its graph or given the situation it models

15 Lesson 1 1

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0

100

200

300

400450500550

50

150

250

350

Gas used (gal)

Dis

tanc

e tr

avel

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i)

d

g

161284

20122007

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The fuel efficiency for a 2007 passenger car was 312 migal For the same model of car the fuel efficiency increased to 356 migal in 2012 The gas tank for this car holds 16 gallons of gas

a Write and graph a linear function that models the distance that each car can travel for a given amount of gas (up to one tankful)

b Write the domain and range of each function using interval notation

c Write and simplify a function ƒ (g) that represents the difference in the distance that the 2012 car can travel and the distance that the 2007 car can travel on the same amount of gas Interpret this function using the graphs of the functions from part a Also find and interpret ƒ (16)

d Write the domain and range of the difference function using set notation

Lesson Performance Task

a For both cars let g be the amount of gas (in gallons) that each car uses and let d be the distance (in miles) that each car travels For the 2007 car the linear model is d 2007 (g) = 312g For the 2012 car the linear model is d 2012 (g) = 356g

b The domain for the 2007 model is [0 16] and the range is [0 4992] The domain for the 2012 model is [0 16] and the range is [0 5696]

c The difference function is f(g) = d 2012 (g) minus d 2007 (g) = 356g minus 312g = 44g This function gives the vertical distance between the graphs of d 2012 (g) and d 2007 (g) For instance when g = 16 the vertical distance between the graphs is f(16) = 44 16 = 704 which means the 2012 car can travel 704 miles farther on a tankful of gas than the 2007 car

d The domain is g⎪0 le g le 16 and the range is f(g)⎪0 le f(g) le 704

Module 1 16 Lesson 1

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A2_MTXESE353930_U1M01L1indd 16 22214 319 AM

EXTENSION ACTIVITY

Have students research the average fuel costs per gallon in 2007 and in 2012 Have students use the data to create a new graph representing the distance each car could travel for a given amount of money (up to the cost of a typical full tank) Ask students to describe the aspects of their graphs

QUESTIONING STRATEGIESWhy must restrictions be placed on the domain The tank only holds at most 16

gallons of gas and at least 0 gallons of gas A graph

with a negative number of gallons of gas or more

than 16 gallons of gas would not make sense for

this situation

Why does the domain contain all of the points in the interval and not just the integer

values The amount of gas used is continuous

There is a distance traveled for any value of g in

the domain

INTEGRATE MATHEMATICAL PROCESSESFocus on CommunicationEncourage students to relate the ranges that they wrote for the difference functions to their graphs Have them determine whether the values in the range make sense in the real-world situation Then have students explain whether it makes sense that as the number of gallons used increases the difference in miles traveled by the two cars also increases

Scoring Rubric2 points Student correctly solves the problem and explains hisher reasoning1 point Student shows good understanding of the problem but does not fully solve or explain hisher reasoning0 points Student does not demonstrate understanding of the problem

Domain Range and End Behavior 16

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Page 4: CorrectionKey=TX-A CorrectionKey=TX-B LESSON 1 . 1 …€¦ ·  · 2017-01-05A2.7.1 Write the domain and range of a function in interval notation, inequalities, and set notation

-4

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Reflect

4 Why is the end behavior of a quadratic function different from the end behavior of a linear function

5 In Part B the ƒ(x)-values decrease as the x-values decrease So why canrsquot you say that f(x) rarr minusinfin as x rarr minusinfin

Your Turn

Write the domain and the range of the function as an inequality using set notation and using interval notation Also describe the end behavior of the function

6 The graph of the quadratic function ƒ(x) = minusx2 is shown

Explain 2 Graphing a Linear Function on a Restricted Domain

Unless otherwise stated a function is assumed to have a domain consisting of all real numbers for which the function is defined Many functionsmdashsuch as linear quadratic and exponential functionsmdashare defined for all real numbers so their domain when written in interval notation is (-infin +infin) Another way to write the set of real numbers is ℝ

Sometimes a function may have a restricted domain If the rule for a function and its restricted domain are given you can draw its graph and then identify its range

Example 2 For the given function and domain draw the graph and identify the range using the same notation as the given domain

ƒ(x) = 3 __ 4 x +2 with domain [-4 4]

Since ƒ(x) = 3 __ 4 x +2 is a linear function the graph is a line segment with endpoints at (-4 ƒ(-4)) or (-4 -1) and (4 ƒ(4)) or (4 5) The endpoints are included in the graph

The range is [-1 5]

Unlike the graph of a linear function the graph of a quadratic function has a turning point

(the vertex) which changes the direction of the graph

The f(x)-values do not decrease without bound They instead approach 0

Domain minusinfin lt x lt +infin x| minusinfin lt x lt +infin (minusinfin +infin)

Range y| y le0 (minusinfin 0]

End behavior As x rarr +infin f(x) rarr -infin As x rarr -infin f(x) rarr -infin

Module 1 8 Lesson 1

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A2_MTXESE353930_U1M01L1indd 8 21415 954 PM

EXPLAIN 2 Graphing a Linear Function on a Restricted Domain

INTEGRATE MATHEMATICAL PROCESSESFocus on Math ConnectionsRemind students that the graph of a function represents the set of ordered pairs produced by the function Help them to see that when they are using a graph to identify the range of a function they are to identify the y-values of those ordered pairs

DIFFERENTIATE INSTRUCTION

Cognitive StrategiesIf students have a difficult time consistently identifying the domain and range of functions encourage them to use the phrase depends on instead of is a function of For example ldquoThe distance traveled by a car depends on the amount of gas in the tankrdquo Help them to see that the elements of the range ldquodepend onrdquo the elements of the domain

Domain Range and End Behavior 8

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Bƒ(x) = -x - 2 with domain x|x gt -3

Since ƒ(x) = -x -2 is a linear function the graph is a ray with its endpoint at (-3 ƒ(-3)) or

The endpoint included in the graph

The range is

Reflect

7 In Part A how does the graph change if the domain is (-4 4) instead of [-4 4]

8 In Part B what is the end behavior as x increases without bound Why canrsquot you talk about the end behavior as x decreases without bound

Your Turn

For the given function and domain draw the graph and identify the range using the same notation as the given domain

9 ƒ(x) = - 1 _ 2 x + 2 with domain -6 le x lt 2 10 f(x) = 2 _ 3 x -1 with domain (minusinfin 3]

(-3 1)

is not

y|y lt 1

The graph no longer includes the endpoints of the segment

As x rarr +infin f(x) rarr -infin Because the domain does not include values of x that are less

than or equal to -3 the values of x cannot decrease without bound

The range is 1 lt y le 5 The range is (minusinfin 1]

Module 1 9 Lesson 1

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A2_MTXESE353930_U1M01L1indd 9 11415 241 AM

LANGUAGE SUPPORT

Connect VocabularyHave students work in pairs Instruct one student to verbally describe the domain range and end behavior of a function without using those three terms Have the other student fill in a graphic organizer with boxes titled Domain Range and End behavior and write in the appropriate values under each box Have students switch roles and repeat the exercise using a different function

QUESTIONING STRATEGIESIf a linear function has a restricted domain must the range consist of a finite number of

elements Explain No If the domain is restricted to

an interval (or intervals) as opposed to a finite

number of elements the range could consist of

infinitely many values For example the range of

the function f (x) = 3x with domain ⎡ ⎣ 0 5 ⎤ ⎦ is ⎡ ⎣ 0 15 ⎤ ⎦

an interval containing infinitely many numbers

If the domain of a linear function consists of n elements how many elements would there be

in the range Explain One if the function is a

constant function or n if it is not In a non-constant

linear function each element of the domain is

paired with a different element of the range

9 Lesson 1 1

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Time (h)

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Explain 3 Modeling with a Linear FunctionRecall that when a real-world situation involves a constant rate of change a linear function is a reasonable model for the situation The situation may require restricting the functionrsquos domain

Example 3 Write a function that models the given situation Determine a domain from the situation graph the function using that domain and identify the range

Joyce jogs at a rate of 1 mile every 10 minutes for a total of 40 minutes (Use inequalities for the domain and range of the function that models this situation)

Joycersquos jogging rate is 01 mimin Her jogging distance d (in miles) at any time t (in minutes) is modeled by d(t) = 01t Since she jogs for 40 minutes the domain is restricted to the interval 0 le t le 40

The range is 0 le d le 4

A candle 6 inches high burns at a rate of 1 inch every 2 hours for 5 hours (Use interval notation for the domain and range of the function that models this situation)

The candlersquos burning rate is inh The candlersquos height h (in inches) at any time t (in hours) is modeled by h(t) =

Since the candle burns for 5 hours the domain is restricted to the

interval ⎡

⎢ ⎣ 0

⎥ ⎦

The range is

-05

6 - 05t

5

[35 6]

Module 1 10 Lesson 1

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A2_MTXESE353930_U1M01L1indd 10 11215 430 PM

EXPLAIN 3 Modeling with a Linear Function

AVOID COMMON ERRORSSome students may erroneously identify the domain of a function that represents a real-world situation as an interval when in fact the domain consists only of specific numbers within the interval such as integers or multiples of a particular rational number Help students to avoid this error by encouraging them to ask themselves whether any number within the interval could be a realistic input value for the situation described by the function

INTEGRATE MATHEMATICAL PROCESSESFocus on ReasoningEncourage students to check their work by considering the reasonableness of the range of the function Have them evaluate whether the values in the range seem realistic for the given situation

Domain Range and End Behavior 10

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Reflect

11 In Part A suppose Joyce jogs for only 30 minutes

A How does the domain change

B How does the graph change

C How does the range change

Your Turn

12 While standing on a moving walkway at an airport you are carried forward 25 feet every 15 seconds for 1 minute Write a function that models this situation Determine the domain from the situation graph the function and identify the range Use set notation for the domain and range

Elaborate

13 If a and b are real numbers such that a lt b use interval notation to write four different intervals having a and b as endpoints Describe what numbers each interval includes

14 What impact does restricting the domain of a linear function have on the graph of the function

15 Essential Question Check-In How does slope determine the end behavior of a linear function with an unrestricted domain

The domain is 0 le t le 30 instead of 0 le t le 40

The graphrsquos right endpoint is (30 3) instead of (40 4)

The range is 0 le d le 3 instead of 0 le d le 4

The walkwayrsquos rate of motion is 5 __ 3 fts The distance d (in feet)

you travel at any time t (in seconds) is modeled by d(t) = 5 __ 3 t

Domain t| 0 le t le 60 range d| 0 le d le 100

[a b] This interval includes all real numbers between a and b including both a and b

[a b) This interval includes all real numbers between a and b including a but not b

(a b] This interval includes all real numbers between a and b including b but not a

(a b) This interval includes all real numbers between a and b but does not include a or b

If slope is positive the f(x)-values increase without bound as the x-values increase without

bound and the f(x)-values decrease without bound as the x-values decrease without bound

If the slope is negative the end behavior reverses The f(x)-values decrease without bound

as the x-values increase without bound and the f(x)-values increase without bound as the

x-values decrease without bound

If the domain is bounded at both ends the graph of the linear function is a line segment

rather than a line If the domain is bounded at only one end the graph of the linear function

is a ray rather than a line

Module 1 11 Lesson 1

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A2_MTXESE353930_U1M01L1indd 11 11415 241 AM

ELABORATE INTEGRATE MATHEMATICAL PROCESSESFocus on CommunicationDiscuss different strategies for determining the range of a function from a graph of the function Have students describe methods they use and illustrate their methods using graphs of different types of functions including those with restricted domains

QUESTIONING STRATEGIESIs it possible that a real-world situation can be modeled by a function whose domain consists

of both positive and negative real numbers If no explain why not If yes give an example Yes

Possible example a function that describes the

relationship between air temperature in degrees

Fahrenheit and dew point at a given level of

humidity The domain consists of all possible air

temperatures in degrees Fahrenheit

SUMMARIZE THE LESSONHow do you identify and represent the domain range and end behavior of a

function To identify the domain find the values of

x for which the function is defined To find the

range find the values of f (x) for each value of x in

the domain There are different ways of

representing the domain and range including using

inequalities set notation and interval notation To

find the end-behavior consider what happens to

the values of the range as the values of the domain

increase or decrease without bound

11 Lesson 1 1

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oughton Mifflin H

arcourt Publishing Company

bull Online Homeworkbull Hints and Helpbull Extra Practice

1 Write the interval shown on the number line as an inequality using set notation and using interval notation

2 Write the interval (5 100] as an inequality and using set notation

3 Write the interval -25 le x lt 30 using set notation and interval notation

4 Write the interval x| -3 lt x lt 5 as an inequality and using interval notation

Write the domain and the range of the function as an inequality using set notation and using interval notation Also describe the end behavior of the function or explain why there is no end behavior

5 The graph of the quadratic functionf (x) = x 2 + 2 is shown

6 The graph of the exponential function f (x) = 3 x is shown

Evaluate Homework and Practice

x ge 5 x|x ge 5 [5 +infin)

x| -25 le x lt 30 [-25 30)

5 lt x le 100 x|5 lt x le 100

-3 lt x lt 5 (-3 5)

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range 2 le y lt +infin y⎪ 2 le y lt +infin ⎡ ⎣ 2 +infin)End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr +infin

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range 0 lt y lt +infin y⎪ 0 lt y lt +infin (0 +infin)End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr 0

Module 1 12 Lesson 1

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A2_MTXESE353930_U1M01L1indd 12 22214 304 AMExercise Depth of Knowledge (DOK) Mathematical Processes

1ndash8 1 Recall of Information 1F Analyze relationships

9ndash10 1 Recall of Information 1E Create and use representations

11 1 Recall of Information 1D Multiple representations

12 2 SkillsConcepts 1A Everyday life

13 2 SkillsConcepts 1G Explain and justify arguments

14 3 Strategic Thinking 1D Multiple representations

EVALUATE

ASSIGNMENT GUIDE

Concepts and Skills Practice

ExploreRepresenting an Interval on a Number Line

Exercise 1ndash4

Example 1Identifying a Functionrsquos Domain Range and End Behavior from its Graph

Exercises 5ndash8

Example 2Graphing a Linear Function on a Restricted Domain

Exercises 9ndash10

Example 3Modeling with a Linear Function

Exercises 11ndash12

VISUAL CUESSome students may benefit from labeling the endpoints of an interval as included or not included as indicated by the closed circle or open circle on the graph They will then be sure to use the appropriate symbols when describing the interval using the different types of notation

CONNECT VOCABULARY Relate end behavior to the shape of the graph of different functions Have students use words to describe the end behavior of each function by looking at the graph For example a function ƒ (x) appears to rise for positive x-values and fall for negative x-values

Domain Range and End Behavior 12

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7 The graph of the linear function g (x) = 2x - 2 is shown

8 The graph of a function is shown

For the given function and domain draw the graph and identify the range using the same notation as the given domain

9 f(x) = minusx + 5 with domain [minus3 2] 10 f(x) = 3 _ 2 x + 1 with domain x |x gt minus 2

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range minusinfin lt y lt +infin y⎪ minusinfin lt y lt +infin (minusinfin +infin) End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr -infin

Domain minus4 le x le 4 x⎪ minus4 le x le 4 [minus4 4]

Range 0 le y le 4 y⎪ 0 le y le 4 [0 4]

There is no end behavior because the domain is bounded at both ends

Since f (x) = -x + 5 is a linear

function the graph is a line

segment with endpoints at

(-3 f (-3) ) or (minus3 8) and

(2 f(2)) or (2 3) The endpoints

are included in the graph

The range is [3 8]

Since f (x) = 3 _ 2

x + 1 is a linear

function the graph is a ray with

its endpoint at (-2 f (-2) )

or (minus2 minus2) The endpoint is not

included in the graph

The range is y⎪ y gt - 2

Module 1 13 Lesson 1

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A2_MTXESE353930_U1M01L1indd 13 11415 241 AMExercise Depth of Knowledge (DOK) Mathematical Processes

15 2 SkillsConcepts 1E Create and use representations

MULTIPLE REPRESENTATIONSWhen analyzing the graph of a function students may find it easier to first describe the end behavior of the function in words They then can translate their verbal descriptions into algebraic notation making sure that the symbols accurately reflect their descriptions

KINESTHETIC EXPERIENCETo help students correctly identify end behavior suggest that they use a finger to trace along the graph of a function moving first from left to right as x rarr infin and then from right to left as x rarr -infin Help them to match their observations of the behavior of the graph to its correct description and notation

13 Lesson 1 1

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Write a function that models the given situation Determine the domain from the situation graph the function using that domain and identify the range

11 A bicyclist travels at a constant speed of 12 miles per hour for a total of 45 minutes (Use set notation for the domain and range of the function that models this situation)

12 An elevator in a tall building starts at a floor of the building that is 90 meters above the ground The elevator descends 2 meters every 05 second for 6 seconds (Use an inequality for the domain and range of the function that models this situation)

HOT Focus on Higher Order Thinking

13 Explain the Error Cameron sells tickets at a movie theater On Friday night she worked from 4 pm to 10 pm and sold about 25 tickets every hour Cameron says that the number of tickets n she has sold at any time t (in hours) can be modeled by the function n(t) = 25t where the domain is 0 le t le 1 and the range is 0 le n le 25 Is Cameronrsquos function along with the domain and range correct Explain

The bicyclistrsquos speed is 12 mih The distance traveled

d (in miles) at any time t (in hours) is modeled by

d(t) = 12t Since the bicyclist travels for 45 minutes

or 075 hour the domain is restricted to the interval

t⎪0 le t le 075

The range is d⎪0 le d le 9

The elevatorrsquos rate of motion is -4 ms The elevatorrsquos

height h (in meters) at any time t (in seconds) is modeled by

h(t) = 90 - 4t Since the elevator descends for 6 seconds

the domain is restricted to the interval 0 le t le 6

The range is 66 le h le 90

Cameronrsquos function is correct but the domain and range are incorrect Cameron worked for a total of 6 hours so the domain of the function should be 0 le t le 6 After 6 hours Cameron has sold 25 times 6 = 150 tickets So the range of the function should be 0 le n le 150

Module 1 14 Lesson 1

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A2_MTXESE353930_U1M01L1indd 14 11415 241 AM

QUESTIONING STRATEGIESWhen is the graph of a linear function with a restricted domain a line segment When is it a

ray It is a line segment when the domain is a

closed interval It is a ray when the domain is

restricted to real numbers greater than or equal to a

number or less than or equal to a number

AVOID COMMON ERRORSWhen attempting to model a real-world situation students sometimes confuse the dependent and independent variables thus reversing the domain and range Help them to understand that the domain consists of the values represented by the independent variable and that the range values are a function of the values of the domain

Domain Range and End Behavior 14

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14 Multi-Step The graph of the cubic function ƒ(x) = x 3 is shown

a What are the domain range and end behavior of the function (Write the domain and range as an inequality using set notation and using interval notation)

b How is the range of the function affected if the domain is restricted to [-4 4] (Write the range as an inequality using set notation and using interval notation)

c Graph the function with the restricted domain

15 Represent Real-World Situations The John James Audubon Bridge is a cable-stayed bridge in Louisiana that opened in 2011 The height from the bridge deck to the top of the tower where a particular cable is anchored is about 500 feet and the length of that cable is about 1200 feet Draw the cable on a coordinate plane letting the x-axis represent the bridge deck and the y-axis represent the tower (Only use positive values of x and y) Write a linear function whose graph models the cable Identify the domain and range writing each as an inequality using set notation and using interval notation

a Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range minusinfin lt y lt +infin y⎪ minusinfin lt y lt +infin (minusinfin +infin) End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr -infin

b Restricted range -64 le y le 64 y⎪ minus64 le y le +64 [-64 64]

c

Since the cable the bridge deck and the

tower form a right triangle find the length

of the leg that lies on the x-axis by using the

Pythagorean Theorem

a 2 + b 2 = c 2

500 2 + b 2 = 1200 2

b asymp 109 1

slope m = 500 - 0 _ 0 - 1091

= 500 _ -1091 asymp -046

The y-intercept is 500

So the linear function is y = -046x + 500

Domain 0 le x le 1091 x⎪0 le x le 1091 [0 1091]

Range 0 le y le 500 y⎪0 le y le 500 [0 500]

Module 1 15 Lesson 1

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A2_MTXESE353930_U1M01L1indd 15 11415 241 AM

PEERTOPEER DISCUSSIONIs it possible that a linear function with the domain all real numbers could have a range that is not all real numbers Explain Yes the function could be a

constant function such as f (x) = 2 The domain is

all real numbers but the range is 2

You may want to have students work on the modeling questions in pairs thus providing them with an opportunity to discuss each situation with a partner and decide how to best model the situation using a function

JOURNALHave students describe how to identify the domain and range of a function given its graph or given the situation it models

15 Lesson 1 1

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0

100

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300

400450500550

50

150

250

350

Gas used (gal)

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tanc

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avel

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161284

20122007

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The fuel efficiency for a 2007 passenger car was 312 migal For the same model of car the fuel efficiency increased to 356 migal in 2012 The gas tank for this car holds 16 gallons of gas

a Write and graph a linear function that models the distance that each car can travel for a given amount of gas (up to one tankful)

b Write the domain and range of each function using interval notation

c Write and simplify a function ƒ (g) that represents the difference in the distance that the 2012 car can travel and the distance that the 2007 car can travel on the same amount of gas Interpret this function using the graphs of the functions from part a Also find and interpret ƒ (16)

d Write the domain and range of the difference function using set notation

Lesson Performance Task

a For both cars let g be the amount of gas (in gallons) that each car uses and let d be the distance (in miles) that each car travels For the 2007 car the linear model is d 2007 (g) = 312g For the 2012 car the linear model is d 2012 (g) = 356g

b The domain for the 2007 model is [0 16] and the range is [0 4992] The domain for the 2012 model is [0 16] and the range is [0 5696]

c The difference function is f(g) = d 2012 (g) minus d 2007 (g) = 356g minus 312g = 44g This function gives the vertical distance between the graphs of d 2012 (g) and d 2007 (g) For instance when g = 16 the vertical distance between the graphs is f(16) = 44 16 = 704 which means the 2012 car can travel 704 miles farther on a tankful of gas than the 2007 car

d The domain is g⎪0 le g le 16 and the range is f(g)⎪0 le f(g) le 704

Module 1 16 Lesson 1

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A2_MTXESE353930_U1M01L1indd 16 22214 319 AM

EXTENSION ACTIVITY

Have students research the average fuel costs per gallon in 2007 and in 2012 Have students use the data to create a new graph representing the distance each car could travel for a given amount of money (up to the cost of a typical full tank) Ask students to describe the aspects of their graphs

QUESTIONING STRATEGIESWhy must restrictions be placed on the domain The tank only holds at most 16

gallons of gas and at least 0 gallons of gas A graph

with a negative number of gallons of gas or more

than 16 gallons of gas would not make sense for

this situation

Why does the domain contain all of the points in the interval and not just the integer

values The amount of gas used is continuous

There is a distance traveled for any value of g in

the domain

INTEGRATE MATHEMATICAL PROCESSESFocus on CommunicationEncourage students to relate the ranges that they wrote for the difference functions to their graphs Have them determine whether the values in the range make sense in the real-world situation Then have students explain whether it makes sense that as the number of gallons used increases the difference in miles traveled by the two cars also increases

Scoring Rubric2 points Student correctly solves the problem and explains hisher reasoning1 point Student shows good understanding of the problem but does not fully solve or explain hisher reasoning0 points Student does not demonstrate understanding of the problem

Domain Range and End Behavior 16

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Page 5: CorrectionKey=TX-A CorrectionKey=TX-B LESSON 1 . 1 …€¦ ·  · 2017-01-05A2.7.1 Write the domain and range of a function in interval notation, inequalities, and set notation

-4

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0 42

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pan

y

Bƒ(x) = -x - 2 with domain x|x gt -3

Since ƒ(x) = -x -2 is a linear function the graph is a ray with its endpoint at (-3 ƒ(-3)) or

The endpoint included in the graph

The range is

Reflect

7 In Part A how does the graph change if the domain is (-4 4) instead of [-4 4]

8 In Part B what is the end behavior as x increases without bound Why canrsquot you talk about the end behavior as x decreases without bound

Your Turn

For the given function and domain draw the graph and identify the range using the same notation as the given domain

9 ƒ(x) = - 1 _ 2 x + 2 with domain -6 le x lt 2 10 f(x) = 2 _ 3 x -1 with domain (minusinfin 3]

(-3 1)

is not

y|y lt 1

The graph no longer includes the endpoints of the segment

As x rarr +infin f(x) rarr -infin Because the domain does not include values of x that are less

than or equal to -3 the values of x cannot decrease without bound

The range is 1 lt y le 5 The range is (minusinfin 1]

Module 1 9 Lesson 1

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A2_MTXESE353930_U1M01L1indd 9 11415 241 AM

LANGUAGE SUPPORT

Connect VocabularyHave students work in pairs Instruct one student to verbally describe the domain range and end behavior of a function without using those three terms Have the other student fill in a graphic organizer with boxes titled Domain Range and End behavior and write in the appropriate values under each box Have students switch roles and repeat the exercise using a different function

QUESTIONING STRATEGIESIf a linear function has a restricted domain must the range consist of a finite number of

elements Explain No If the domain is restricted to

an interval (or intervals) as opposed to a finite

number of elements the range could consist of

infinitely many values For example the range of

the function f (x) = 3x with domain ⎡ ⎣ 0 5 ⎤ ⎦ is ⎡ ⎣ 0 15 ⎤ ⎦

an interval containing infinitely many numbers

If the domain of a linear function consists of n elements how many elements would there be

in the range Explain One if the function is a

constant function or n if it is not In a non-constant

linear function each element of the domain is

paired with a different element of the range

9 Lesson 1 1

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tanc

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40302010

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5

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Time (h)

Hei

ght (

in)

h

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4321 8765

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age C

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Bounce

Up

perC

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ages

Explain 3 Modeling with a Linear FunctionRecall that when a real-world situation involves a constant rate of change a linear function is a reasonable model for the situation The situation may require restricting the functionrsquos domain

Example 3 Write a function that models the given situation Determine a domain from the situation graph the function using that domain and identify the range

Joyce jogs at a rate of 1 mile every 10 minutes for a total of 40 minutes (Use inequalities for the domain and range of the function that models this situation)

Joycersquos jogging rate is 01 mimin Her jogging distance d (in miles) at any time t (in minutes) is modeled by d(t) = 01t Since she jogs for 40 minutes the domain is restricted to the interval 0 le t le 40

The range is 0 le d le 4

A candle 6 inches high burns at a rate of 1 inch every 2 hours for 5 hours (Use interval notation for the domain and range of the function that models this situation)

The candlersquos burning rate is inh The candlersquos height h (in inches) at any time t (in hours) is modeled by h(t) =

Since the candle burns for 5 hours the domain is restricted to the

interval ⎡

⎢ ⎣ 0

⎥ ⎦

The range is

-05

6 - 05t

5

[35 6]

Module 1 10 Lesson 1

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A2_MTXESE353930_U1M01L1indd 10 11215 430 PM

EXPLAIN 3 Modeling with a Linear Function

AVOID COMMON ERRORSSome students may erroneously identify the domain of a function that represents a real-world situation as an interval when in fact the domain consists only of specific numbers within the interval such as integers or multiples of a particular rational number Help students to avoid this error by encouraging them to ask themselves whether any number within the interval could be a realistic input value for the situation described by the function

INTEGRATE MATHEMATICAL PROCESSESFocus on ReasoningEncourage students to check their work by considering the reasonableness of the range of the function Have them evaluate whether the values in the range seem realistic for the given situation

Domain Range and End Behavior 10

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

0

20

40

60

80

10

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70

10090

Time (s)

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tanc

e on

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(ft)

d

t

80604020

copy H

oug

hton

Mif

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cour

t Pub

lishi

ng

Com

pan

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Reflect

11 In Part A suppose Joyce jogs for only 30 minutes

A How does the domain change

B How does the graph change

C How does the range change

Your Turn

12 While standing on a moving walkway at an airport you are carried forward 25 feet every 15 seconds for 1 minute Write a function that models this situation Determine the domain from the situation graph the function and identify the range Use set notation for the domain and range

Elaborate

13 If a and b are real numbers such that a lt b use interval notation to write four different intervals having a and b as endpoints Describe what numbers each interval includes

14 What impact does restricting the domain of a linear function have on the graph of the function

15 Essential Question Check-In How does slope determine the end behavior of a linear function with an unrestricted domain

The domain is 0 le t le 30 instead of 0 le t le 40

The graphrsquos right endpoint is (30 3) instead of (40 4)

The range is 0 le d le 3 instead of 0 le d le 4

The walkwayrsquos rate of motion is 5 __ 3 fts The distance d (in feet)

you travel at any time t (in seconds) is modeled by d(t) = 5 __ 3 t

Domain t| 0 le t le 60 range d| 0 le d le 100

[a b] This interval includes all real numbers between a and b including both a and b

[a b) This interval includes all real numbers between a and b including a but not b

(a b] This interval includes all real numbers between a and b including b but not a

(a b) This interval includes all real numbers between a and b but does not include a or b

If slope is positive the f(x)-values increase without bound as the x-values increase without

bound and the f(x)-values decrease without bound as the x-values decrease without bound

If the slope is negative the end behavior reverses The f(x)-values decrease without bound

as the x-values increase without bound and the f(x)-values increase without bound as the

x-values decrease without bound

If the domain is bounded at both ends the graph of the linear function is a line segment

rather than a line If the domain is bounded at only one end the graph of the linear function

is a ray rather than a line

Module 1 11 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 11 11415 241 AM

ELABORATE INTEGRATE MATHEMATICAL PROCESSESFocus on CommunicationDiscuss different strategies for determining the range of a function from a graph of the function Have students describe methods they use and illustrate their methods using graphs of different types of functions including those with restricted domains

QUESTIONING STRATEGIESIs it possible that a real-world situation can be modeled by a function whose domain consists

of both positive and negative real numbers If no explain why not If yes give an example Yes

Possible example a function that describes the

relationship between air temperature in degrees

Fahrenheit and dew point at a given level of

humidity The domain consists of all possible air

temperatures in degrees Fahrenheit

SUMMARIZE THE LESSONHow do you identify and represent the domain range and end behavior of a

function To identify the domain find the values of

x for which the function is defined To find the

range find the values of f (x) for each value of x in

the domain There are different ways of

representing the domain and range including using

inequalities set notation and interval notation To

find the end-behavior consider what happens to

the values of the range as the values of the domain

increase or decrease without bound

11 Lesson 1 1

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oughton Mifflin H

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bull Online Homeworkbull Hints and Helpbull Extra Practice

1 Write the interval shown on the number line as an inequality using set notation and using interval notation

2 Write the interval (5 100] as an inequality and using set notation

3 Write the interval -25 le x lt 30 using set notation and interval notation

4 Write the interval x| -3 lt x lt 5 as an inequality and using interval notation

Write the domain and the range of the function as an inequality using set notation and using interval notation Also describe the end behavior of the function or explain why there is no end behavior

5 The graph of the quadratic functionf (x) = x 2 + 2 is shown

6 The graph of the exponential function f (x) = 3 x is shown

Evaluate Homework and Practice

x ge 5 x|x ge 5 [5 +infin)

x| -25 le x lt 30 [-25 30)

5 lt x le 100 x|5 lt x le 100

-3 lt x lt 5 (-3 5)

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range 2 le y lt +infin y⎪ 2 le y lt +infin ⎡ ⎣ 2 +infin)End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr +infin

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range 0 lt y lt +infin y⎪ 0 lt y lt +infin (0 +infin)End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr 0

Module 1 12 Lesson 1

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-A

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-A

A2_MTXESE353930_U1M01L1indd 12 22214 304 AMExercise Depth of Knowledge (DOK) Mathematical Processes

1ndash8 1 Recall of Information 1F Analyze relationships

9ndash10 1 Recall of Information 1E Create and use representations

11 1 Recall of Information 1D Multiple representations

12 2 SkillsConcepts 1A Everyday life

13 2 SkillsConcepts 1G Explain and justify arguments

14 3 Strategic Thinking 1D Multiple representations

EVALUATE

ASSIGNMENT GUIDE

Concepts and Skills Practice

ExploreRepresenting an Interval on a Number Line

Exercise 1ndash4

Example 1Identifying a Functionrsquos Domain Range and End Behavior from its Graph

Exercises 5ndash8

Example 2Graphing a Linear Function on a Restricted Domain

Exercises 9ndash10

Example 3Modeling with a Linear Function

Exercises 11ndash12

VISUAL CUESSome students may benefit from labeling the endpoints of an interval as included or not included as indicated by the closed circle or open circle on the graph They will then be sure to use the appropriate symbols when describing the interval using the different types of notation

CONNECT VOCABULARY Relate end behavior to the shape of the graph of different functions Have students use words to describe the end behavior of each function by looking at the graph For example a function ƒ (x) appears to rise for positive x-values and fall for negative x-values

Domain Range and End Behavior 12

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

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7 The graph of the linear function g (x) = 2x - 2 is shown

8 The graph of a function is shown

For the given function and domain draw the graph and identify the range using the same notation as the given domain

9 f(x) = minusx + 5 with domain [minus3 2] 10 f(x) = 3 _ 2 x + 1 with domain x |x gt minus 2

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range minusinfin lt y lt +infin y⎪ minusinfin lt y lt +infin (minusinfin +infin) End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr -infin

Domain minus4 le x le 4 x⎪ minus4 le x le 4 [minus4 4]

Range 0 le y le 4 y⎪ 0 le y le 4 [0 4]

There is no end behavior because the domain is bounded at both ends

Since f (x) = -x + 5 is a linear

function the graph is a line

segment with endpoints at

(-3 f (-3) ) or (minus3 8) and

(2 f(2)) or (2 3) The endpoints

are included in the graph

The range is [3 8]

Since f (x) = 3 _ 2

x + 1 is a linear

function the graph is a ray with

its endpoint at (-2 f (-2) )

or (minus2 minus2) The endpoint is not

included in the graph

The range is y⎪ y gt - 2

Module 1 13 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 13 11415 241 AMExercise Depth of Knowledge (DOK) Mathematical Processes

15 2 SkillsConcepts 1E Create and use representations

MULTIPLE REPRESENTATIONSWhen analyzing the graph of a function students may find it easier to first describe the end behavior of the function in words They then can translate their verbal descriptions into algebraic notation making sure that the symbols accurately reflect their descriptions

KINESTHETIC EXPERIENCETo help students correctly identify end behavior suggest that they use a finger to trace along the graph of a function moving first from left to right as x rarr infin and then from right to left as x rarr -infin Help them to match their observations of the behavior of the graph to its correct description and notation

13 Lesson 1 1

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CaroA

lamy

Write a function that models the given situation Determine the domain from the situation graph the function using that domain and identify the range

11 A bicyclist travels at a constant speed of 12 miles per hour for a total of 45 minutes (Use set notation for the domain and range of the function that models this situation)

12 An elevator in a tall building starts at a floor of the building that is 90 meters above the ground The elevator descends 2 meters every 05 second for 6 seconds (Use an inequality for the domain and range of the function that models this situation)

HOT Focus on Higher Order Thinking

13 Explain the Error Cameron sells tickets at a movie theater On Friday night she worked from 4 pm to 10 pm and sold about 25 tickets every hour Cameron says that the number of tickets n she has sold at any time t (in hours) can be modeled by the function n(t) = 25t where the domain is 0 le t le 1 and the range is 0 le n le 25 Is Cameronrsquos function along with the domain and range correct Explain

The bicyclistrsquos speed is 12 mih The distance traveled

d (in miles) at any time t (in hours) is modeled by

d(t) = 12t Since the bicyclist travels for 45 minutes

or 075 hour the domain is restricted to the interval

t⎪0 le t le 075

The range is d⎪0 le d le 9

The elevatorrsquos rate of motion is -4 ms The elevatorrsquos

height h (in meters) at any time t (in seconds) is modeled by

h(t) = 90 - 4t Since the elevator descends for 6 seconds

the domain is restricted to the interval 0 le t le 6

The range is 66 le h le 90

Cameronrsquos function is correct but the domain and range are incorrect Cameron worked for a total of 6 hours so the domain of the function should be 0 le t le 6 After 6 hours Cameron has sold 25 times 6 = 150 tickets So the range of the function should be 0 le n le 150

Module 1 14 Lesson 1

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DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 14 11415 241 AM

QUESTIONING STRATEGIESWhen is the graph of a linear function with a restricted domain a line segment When is it a

ray It is a line segment when the domain is a

closed interval It is a ray when the domain is

restricted to real numbers greater than or equal to a

number or less than or equal to a number

AVOID COMMON ERRORSWhen attempting to model a real-world situation students sometimes confuse the dependent and independent variables thus reversing the domain and range Help them to understand that the domain consists of the values represented by the independent variable and that the range values are a function of the values of the domain

Domain Range and End Behavior 14

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

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Distance from tower (ft)

Hei

ght a

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(ft)

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400200 800 1000600

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14 Multi-Step The graph of the cubic function ƒ(x) = x 3 is shown

a What are the domain range and end behavior of the function (Write the domain and range as an inequality using set notation and using interval notation)

b How is the range of the function affected if the domain is restricted to [-4 4] (Write the range as an inequality using set notation and using interval notation)

c Graph the function with the restricted domain

15 Represent Real-World Situations The John James Audubon Bridge is a cable-stayed bridge in Louisiana that opened in 2011 The height from the bridge deck to the top of the tower where a particular cable is anchored is about 500 feet and the length of that cable is about 1200 feet Draw the cable on a coordinate plane letting the x-axis represent the bridge deck and the y-axis represent the tower (Only use positive values of x and y) Write a linear function whose graph models the cable Identify the domain and range writing each as an inequality using set notation and using interval notation

a Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range minusinfin lt y lt +infin y⎪ minusinfin lt y lt +infin (minusinfin +infin) End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr -infin

b Restricted range -64 le y le 64 y⎪ minus64 le y le +64 [-64 64]

c

Since the cable the bridge deck and the

tower form a right triangle find the length

of the leg that lies on the x-axis by using the

Pythagorean Theorem

a 2 + b 2 = c 2

500 2 + b 2 = 1200 2

b asymp 109 1

slope m = 500 - 0 _ 0 - 1091

= 500 _ -1091 asymp -046

The y-intercept is 500

So the linear function is y = -046x + 500

Domain 0 le x le 1091 x⎪0 le x le 1091 [0 1091]

Range 0 le y le 500 y⎪0 le y le 500 [0 500]

Module 1 15 Lesson 1

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A2_MTXESE353930_U1M01L1indd 15 11415 241 AM

PEERTOPEER DISCUSSIONIs it possible that a linear function with the domain all real numbers could have a range that is not all real numbers Explain Yes the function could be a

constant function such as f (x) = 2 The domain is

all real numbers but the range is 2

You may want to have students work on the modeling questions in pairs thus providing them with an opportunity to discuss each situation with a partner and decide how to best model the situation using a function

JOURNALHave students describe how to identify the domain and range of a function given its graph or given the situation it models

15 Lesson 1 1

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0

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400450500550

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Gas used (gal)

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avel

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i)

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161284

20122007

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The fuel efficiency for a 2007 passenger car was 312 migal For the same model of car the fuel efficiency increased to 356 migal in 2012 The gas tank for this car holds 16 gallons of gas

a Write and graph a linear function that models the distance that each car can travel for a given amount of gas (up to one tankful)

b Write the domain and range of each function using interval notation

c Write and simplify a function ƒ (g) that represents the difference in the distance that the 2012 car can travel and the distance that the 2007 car can travel on the same amount of gas Interpret this function using the graphs of the functions from part a Also find and interpret ƒ (16)

d Write the domain and range of the difference function using set notation

Lesson Performance Task

a For both cars let g be the amount of gas (in gallons) that each car uses and let d be the distance (in miles) that each car travels For the 2007 car the linear model is d 2007 (g) = 312g For the 2012 car the linear model is d 2012 (g) = 356g

b The domain for the 2007 model is [0 16] and the range is [0 4992] The domain for the 2012 model is [0 16] and the range is [0 5696]

c The difference function is f(g) = d 2012 (g) minus d 2007 (g) = 356g minus 312g = 44g This function gives the vertical distance between the graphs of d 2012 (g) and d 2007 (g) For instance when g = 16 the vertical distance between the graphs is f(16) = 44 16 = 704 which means the 2012 car can travel 704 miles farther on a tankful of gas than the 2007 car

d The domain is g⎪0 le g le 16 and the range is f(g)⎪0 le f(g) le 704

Module 1 16 Lesson 1

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A2_MTXESE353930_U1M01L1indd 16 22214 319 AM

EXTENSION ACTIVITY

Have students research the average fuel costs per gallon in 2007 and in 2012 Have students use the data to create a new graph representing the distance each car could travel for a given amount of money (up to the cost of a typical full tank) Ask students to describe the aspects of their graphs

QUESTIONING STRATEGIESWhy must restrictions be placed on the domain The tank only holds at most 16

gallons of gas and at least 0 gallons of gas A graph

with a negative number of gallons of gas or more

than 16 gallons of gas would not make sense for

this situation

Why does the domain contain all of the points in the interval and not just the integer

values The amount of gas used is continuous

There is a distance traveled for any value of g in

the domain

INTEGRATE MATHEMATICAL PROCESSESFocus on CommunicationEncourage students to relate the ranges that they wrote for the difference functions to their graphs Have them determine whether the values in the range make sense in the real-world situation Then have students explain whether it makes sense that as the number of gallons used increases the difference in miles traveled by the two cars also increases

Scoring Rubric2 points Student correctly solves the problem and explains hisher reasoning1 point Student shows good understanding of the problem but does not fully solve or explain hisher reasoning0 points Student does not demonstrate understanding of the problem

Domain Range and End Behavior 16

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Page 6: CorrectionKey=TX-A CorrectionKey=TX-B LESSON 1 . 1 …€¦ ·  · 2017-01-05A2.7.1 Write the domain and range of a function in interval notation, inequalities, and set notation

0

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e (m

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in)

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Bounce

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Explain 3 Modeling with a Linear FunctionRecall that when a real-world situation involves a constant rate of change a linear function is a reasonable model for the situation The situation may require restricting the functionrsquos domain

Example 3 Write a function that models the given situation Determine a domain from the situation graph the function using that domain and identify the range

Joyce jogs at a rate of 1 mile every 10 minutes for a total of 40 minutes (Use inequalities for the domain and range of the function that models this situation)

Joycersquos jogging rate is 01 mimin Her jogging distance d (in miles) at any time t (in minutes) is modeled by d(t) = 01t Since she jogs for 40 minutes the domain is restricted to the interval 0 le t le 40

The range is 0 le d le 4

A candle 6 inches high burns at a rate of 1 inch every 2 hours for 5 hours (Use interval notation for the domain and range of the function that models this situation)

The candlersquos burning rate is inh The candlersquos height h (in inches) at any time t (in hours) is modeled by h(t) =

Since the candle burns for 5 hours the domain is restricted to the

interval ⎡

⎢ ⎣ 0

⎥ ⎦

The range is

-05

6 - 05t

5

[35 6]

Module 1 10 Lesson 1

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DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 10 11215 430 PM

EXPLAIN 3 Modeling with a Linear Function

AVOID COMMON ERRORSSome students may erroneously identify the domain of a function that represents a real-world situation as an interval when in fact the domain consists only of specific numbers within the interval such as integers or multiples of a particular rational number Help students to avoid this error by encouraging them to ask themselves whether any number within the interval could be a realistic input value for the situation described by the function

INTEGRATE MATHEMATICAL PROCESSESFocus on ReasoningEncourage students to check their work by considering the reasonableness of the range of the function Have them evaluate whether the values in the range seem realistic for the given situation

Domain Range and End Behavior 10

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Time (s)

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Reflect

11 In Part A suppose Joyce jogs for only 30 minutes

A How does the domain change

B How does the graph change

C How does the range change

Your Turn

12 While standing on a moving walkway at an airport you are carried forward 25 feet every 15 seconds for 1 minute Write a function that models this situation Determine the domain from the situation graph the function and identify the range Use set notation for the domain and range

Elaborate

13 If a and b are real numbers such that a lt b use interval notation to write four different intervals having a and b as endpoints Describe what numbers each interval includes

14 What impact does restricting the domain of a linear function have on the graph of the function

15 Essential Question Check-In How does slope determine the end behavior of a linear function with an unrestricted domain

The domain is 0 le t le 30 instead of 0 le t le 40

The graphrsquos right endpoint is (30 3) instead of (40 4)

The range is 0 le d le 3 instead of 0 le d le 4

The walkwayrsquos rate of motion is 5 __ 3 fts The distance d (in feet)

you travel at any time t (in seconds) is modeled by d(t) = 5 __ 3 t

Domain t| 0 le t le 60 range d| 0 le d le 100

[a b] This interval includes all real numbers between a and b including both a and b

[a b) This interval includes all real numbers between a and b including a but not b

(a b] This interval includes all real numbers between a and b including b but not a

(a b) This interval includes all real numbers between a and b but does not include a or b

If slope is positive the f(x)-values increase without bound as the x-values increase without

bound and the f(x)-values decrease without bound as the x-values decrease without bound

If the slope is negative the end behavior reverses The f(x)-values decrease without bound

as the x-values increase without bound and the f(x)-values increase without bound as the

x-values decrease without bound

If the domain is bounded at both ends the graph of the linear function is a line segment

rather than a line If the domain is bounded at only one end the graph of the linear function

is a ray rather than a line

Module 1 11 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 11 11415 241 AM

ELABORATE INTEGRATE MATHEMATICAL PROCESSESFocus on CommunicationDiscuss different strategies for determining the range of a function from a graph of the function Have students describe methods they use and illustrate their methods using graphs of different types of functions including those with restricted domains

QUESTIONING STRATEGIESIs it possible that a real-world situation can be modeled by a function whose domain consists

of both positive and negative real numbers If no explain why not If yes give an example Yes

Possible example a function that describes the

relationship between air temperature in degrees

Fahrenheit and dew point at a given level of

humidity The domain consists of all possible air

temperatures in degrees Fahrenheit

SUMMARIZE THE LESSONHow do you identify and represent the domain range and end behavior of a

function To identify the domain find the values of

x for which the function is defined To find the

range find the values of f (x) for each value of x in

the domain There are different ways of

representing the domain and range including using

inequalities set notation and interval notation To

find the end-behavior consider what happens to

the values of the range as the values of the domain

increase or decrease without bound

11 Lesson 1 1

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0 42

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3 4 5 6 7 8

copy H

oughton Mifflin H

arcourt Publishing Company

bull Online Homeworkbull Hints and Helpbull Extra Practice

1 Write the interval shown on the number line as an inequality using set notation and using interval notation

2 Write the interval (5 100] as an inequality and using set notation

3 Write the interval -25 le x lt 30 using set notation and interval notation

4 Write the interval x| -3 lt x lt 5 as an inequality and using interval notation

Write the domain and the range of the function as an inequality using set notation and using interval notation Also describe the end behavior of the function or explain why there is no end behavior

5 The graph of the quadratic functionf (x) = x 2 + 2 is shown

6 The graph of the exponential function f (x) = 3 x is shown

Evaluate Homework and Practice

x ge 5 x|x ge 5 [5 +infin)

x| -25 le x lt 30 [-25 30)

5 lt x le 100 x|5 lt x le 100

-3 lt x lt 5 (-3 5)

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range 2 le y lt +infin y⎪ 2 le y lt +infin ⎡ ⎣ 2 +infin)End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr +infin

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range 0 lt y lt +infin y⎪ 0 lt y lt +infin (0 +infin)End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr 0

Module 1 12 Lesson 1

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-A

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-A

A2_MTXESE353930_U1M01L1indd 12 22214 304 AMExercise Depth of Knowledge (DOK) Mathematical Processes

1ndash8 1 Recall of Information 1F Analyze relationships

9ndash10 1 Recall of Information 1E Create and use representations

11 1 Recall of Information 1D Multiple representations

12 2 SkillsConcepts 1A Everyday life

13 2 SkillsConcepts 1G Explain and justify arguments

14 3 Strategic Thinking 1D Multiple representations

EVALUATE

ASSIGNMENT GUIDE

Concepts and Skills Practice

ExploreRepresenting an Interval on a Number Line

Exercise 1ndash4

Example 1Identifying a Functionrsquos Domain Range and End Behavior from its Graph

Exercises 5ndash8

Example 2Graphing a Linear Function on a Restricted Domain

Exercises 9ndash10

Example 3Modeling with a Linear Function

Exercises 11ndash12

VISUAL CUESSome students may benefit from labeling the endpoints of an interval as included or not included as indicated by the closed circle or open circle on the graph They will then be sure to use the appropriate symbols when describing the interval using the different types of notation

CONNECT VOCABULARY Relate end behavior to the shape of the graph of different functions Have students use words to describe the end behavior of each function by looking at the graph For example a function ƒ (x) appears to rise for positive x-values and fall for negative x-values

Domain Range and End Behavior 12

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

-2

4

2

y

0 42

x

-2-4-2

-4

2

y

0 42

x

-2-4

4

2

8

6

y

0 42

x

-2-4 -4

-2

4

2

y

0 42

x

-2-4

copy H

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Com

pan

y

7 The graph of the linear function g (x) = 2x - 2 is shown

8 The graph of a function is shown

For the given function and domain draw the graph and identify the range using the same notation as the given domain

9 f(x) = minusx + 5 with domain [minus3 2] 10 f(x) = 3 _ 2 x + 1 with domain x |x gt minus 2

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range minusinfin lt y lt +infin y⎪ minusinfin lt y lt +infin (minusinfin +infin) End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr -infin

Domain minus4 le x le 4 x⎪ minus4 le x le 4 [minus4 4]

Range 0 le y le 4 y⎪ 0 le y le 4 [0 4]

There is no end behavior because the domain is bounded at both ends

Since f (x) = -x + 5 is a linear

function the graph is a line

segment with endpoints at

(-3 f (-3) ) or (minus3 8) and

(2 f(2)) or (2 3) The endpoints

are included in the graph

The range is [3 8]

Since f (x) = 3 _ 2

x + 1 is a linear

function the graph is a ray with

its endpoint at (-2 f (-2) )

or (minus2 minus2) The endpoint is not

included in the graph

The range is y⎪ y gt - 2

Module 1 13 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 13 11415 241 AMExercise Depth of Knowledge (DOK) Mathematical Processes

15 2 SkillsConcepts 1E Create and use representations

MULTIPLE REPRESENTATIONSWhen analyzing the graph of a function students may find it easier to first describe the end behavior of the function in words They then can translate their verbal descriptions into algebraic notation making sure that the symbols accurately reflect their descriptions

KINESTHETIC EXPERIENCETo help students correctly identify end behavior suggest that they use a finger to trace along the graph of a function moving first from left to right as x rarr infin and then from right to left as x rarr -infin Help them to match their observations of the behavior of the graph to its correct description and notation

13 Lesson 1 1

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

0

2

4

6

89

1

3

5

7

Time (h)D

ista

nce

trav

eled

(mi)

d

t

0402 0806

0

20

40

60

8090

10

30

50

70

Time (s)

Hei

ght a

bove

gro

und

(m) h

t

8642 7531

copy H

oug

hton Mifflin H

arcourt Publishin

g Com

pany bull Im

age C

redits copy

CaroA

lamy

Write a function that models the given situation Determine the domain from the situation graph the function using that domain and identify the range

11 A bicyclist travels at a constant speed of 12 miles per hour for a total of 45 minutes (Use set notation for the domain and range of the function that models this situation)

12 An elevator in a tall building starts at a floor of the building that is 90 meters above the ground The elevator descends 2 meters every 05 second for 6 seconds (Use an inequality for the domain and range of the function that models this situation)

HOT Focus on Higher Order Thinking

13 Explain the Error Cameron sells tickets at a movie theater On Friday night she worked from 4 pm to 10 pm and sold about 25 tickets every hour Cameron says that the number of tickets n she has sold at any time t (in hours) can be modeled by the function n(t) = 25t where the domain is 0 le t le 1 and the range is 0 le n le 25 Is Cameronrsquos function along with the domain and range correct Explain

The bicyclistrsquos speed is 12 mih The distance traveled

d (in miles) at any time t (in hours) is modeled by

d(t) = 12t Since the bicyclist travels for 45 minutes

or 075 hour the domain is restricted to the interval

t⎪0 le t le 075

The range is d⎪0 le d le 9

The elevatorrsquos rate of motion is -4 ms The elevatorrsquos

height h (in meters) at any time t (in seconds) is modeled by

h(t) = 90 - 4t Since the elevator descends for 6 seconds

the domain is restricted to the interval 0 le t le 6

The range is 66 le h le 90

Cameronrsquos function is correct but the domain and range are incorrect Cameron worked for a total of 6 hours so the domain of the function should be 0 le t le 6 After 6 hours Cameron has sold 25 times 6 = 150 tickets So the range of the function should be 0 le n le 150

Module 1 14 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 14 11415 241 AM

QUESTIONING STRATEGIESWhen is the graph of a linear function with a restricted domain a line segment When is it a

ray It is a line segment when the domain is a

closed interval It is a ray when the domain is

restricted to real numbers greater than or equal to a

number or less than or equal to a number

AVOID COMMON ERRORSWhen attempting to model a real-world situation students sometimes confuse the dependent and independent variables thus reversing the domain and range Help them to understand that the domain consists of the values represented by the independent variable and that the range values are a function of the values of the domain

Domain Range and End Behavior 14

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

y

x2 4-4

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-50

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y

x2 4-4

100

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-100

-50

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200

400

600

800

Distance from tower (ft)

Hei

ght a

bove

bri

dge

deck

(ft)

y

x

400200 800 1000600

copy H

oug

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t Pub

lishi

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14 Multi-Step The graph of the cubic function ƒ(x) = x 3 is shown

a What are the domain range and end behavior of the function (Write the domain and range as an inequality using set notation and using interval notation)

b How is the range of the function affected if the domain is restricted to [-4 4] (Write the range as an inequality using set notation and using interval notation)

c Graph the function with the restricted domain

15 Represent Real-World Situations The John James Audubon Bridge is a cable-stayed bridge in Louisiana that opened in 2011 The height from the bridge deck to the top of the tower where a particular cable is anchored is about 500 feet and the length of that cable is about 1200 feet Draw the cable on a coordinate plane letting the x-axis represent the bridge deck and the y-axis represent the tower (Only use positive values of x and y) Write a linear function whose graph models the cable Identify the domain and range writing each as an inequality using set notation and using interval notation

a Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range minusinfin lt y lt +infin y⎪ minusinfin lt y lt +infin (minusinfin +infin) End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr -infin

b Restricted range -64 le y le 64 y⎪ minus64 le y le +64 [-64 64]

c

Since the cable the bridge deck and the

tower form a right triangle find the length

of the leg that lies on the x-axis by using the

Pythagorean Theorem

a 2 + b 2 = c 2

500 2 + b 2 = 1200 2

b asymp 109 1

slope m = 500 - 0 _ 0 - 1091

= 500 _ -1091 asymp -046

The y-intercept is 500

So the linear function is y = -046x + 500

Domain 0 le x le 1091 x⎪0 le x le 1091 [0 1091]

Range 0 le y le 500 y⎪0 le y le 500 [0 500]

Module 1 15 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 15 11415 241 AM

PEERTOPEER DISCUSSIONIs it possible that a linear function with the domain all real numbers could have a range that is not all real numbers Explain Yes the function could be a

constant function such as f (x) = 2 The domain is

all real numbers but the range is 2

You may want to have students work on the modeling questions in pairs thus providing them with an opportunity to discuss each situation with a partner and decide how to best model the situation using a function

JOURNALHave students describe how to identify the domain and range of a function given its graph or given the situation it models

15 Lesson 1 1

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

0

100

200

300

400450500550

50

150

250

350

Gas used (gal)

Dis

tanc

e tr

avel

ed (m

i)

d

g

161284

20122007

copy H

oug

hton Mifflin H

arcourt Publishin

g Com

pany

The fuel efficiency for a 2007 passenger car was 312 migal For the same model of car the fuel efficiency increased to 356 migal in 2012 The gas tank for this car holds 16 gallons of gas

a Write and graph a linear function that models the distance that each car can travel for a given amount of gas (up to one tankful)

b Write the domain and range of each function using interval notation

c Write and simplify a function ƒ (g) that represents the difference in the distance that the 2012 car can travel and the distance that the 2007 car can travel on the same amount of gas Interpret this function using the graphs of the functions from part a Also find and interpret ƒ (16)

d Write the domain and range of the difference function using set notation

Lesson Performance Task

a For both cars let g be the amount of gas (in gallons) that each car uses and let d be the distance (in miles) that each car travels For the 2007 car the linear model is d 2007 (g) = 312g For the 2012 car the linear model is d 2012 (g) = 356g

b The domain for the 2007 model is [0 16] and the range is [0 4992] The domain for the 2012 model is [0 16] and the range is [0 5696]

c The difference function is f(g) = d 2012 (g) minus d 2007 (g) = 356g minus 312g = 44g This function gives the vertical distance between the graphs of d 2012 (g) and d 2007 (g) For instance when g = 16 the vertical distance between the graphs is f(16) = 44 16 = 704 which means the 2012 car can travel 704 miles farther on a tankful of gas than the 2007 car

d The domain is g⎪0 le g le 16 and the range is f(g)⎪0 le f(g) le 704

Module 1 16 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-A

A2_MTXESE353930_U1M01L1indd 16 22214 319 AM

EXTENSION ACTIVITY

Have students research the average fuel costs per gallon in 2007 and in 2012 Have students use the data to create a new graph representing the distance each car could travel for a given amount of money (up to the cost of a typical full tank) Ask students to describe the aspects of their graphs

QUESTIONING STRATEGIESWhy must restrictions be placed on the domain The tank only holds at most 16

gallons of gas and at least 0 gallons of gas A graph

with a negative number of gallons of gas or more

than 16 gallons of gas would not make sense for

this situation

Why does the domain contain all of the points in the interval and not just the integer

values The amount of gas used is continuous

There is a distance traveled for any value of g in

the domain

INTEGRATE MATHEMATICAL PROCESSESFocus on CommunicationEncourage students to relate the ranges that they wrote for the difference functions to their graphs Have them determine whether the values in the range make sense in the real-world situation Then have students explain whether it makes sense that as the number of gallons used increases the difference in miles traveled by the two cars also increases

Scoring Rubric2 points Student correctly solves the problem and explains hisher reasoning1 point Student shows good understanding of the problem but does not fully solve or explain hisher reasoning0 points Student does not demonstrate understanding of the problem

Domain Range and End Behavior 16

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

Page 7: CorrectionKey=TX-A CorrectionKey=TX-B LESSON 1 . 1 …€¦ ·  · 2017-01-05A2.7.1 Write the domain and range of a function in interval notation, inequalities, and set notation

0

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10090

Time (s)

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kway

(ft)

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t

80604020

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t Pub

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ng

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Reflect

11 In Part A suppose Joyce jogs for only 30 minutes

A How does the domain change

B How does the graph change

C How does the range change

Your Turn

12 While standing on a moving walkway at an airport you are carried forward 25 feet every 15 seconds for 1 minute Write a function that models this situation Determine the domain from the situation graph the function and identify the range Use set notation for the domain and range

Elaborate

13 If a and b are real numbers such that a lt b use interval notation to write four different intervals having a and b as endpoints Describe what numbers each interval includes

14 What impact does restricting the domain of a linear function have on the graph of the function

15 Essential Question Check-In How does slope determine the end behavior of a linear function with an unrestricted domain

The domain is 0 le t le 30 instead of 0 le t le 40

The graphrsquos right endpoint is (30 3) instead of (40 4)

The range is 0 le d le 3 instead of 0 le d le 4

The walkwayrsquos rate of motion is 5 __ 3 fts The distance d (in feet)

you travel at any time t (in seconds) is modeled by d(t) = 5 __ 3 t

Domain t| 0 le t le 60 range d| 0 le d le 100

[a b] This interval includes all real numbers between a and b including both a and b

[a b) This interval includes all real numbers between a and b including a but not b

(a b] This interval includes all real numbers between a and b including b but not a

(a b) This interval includes all real numbers between a and b but does not include a or b

If slope is positive the f(x)-values increase without bound as the x-values increase without

bound and the f(x)-values decrease without bound as the x-values decrease without bound

If the slope is negative the end behavior reverses The f(x)-values decrease without bound

as the x-values increase without bound and the f(x)-values increase without bound as the

x-values decrease without bound

If the domain is bounded at both ends the graph of the linear function is a line segment

rather than a line If the domain is bounded at only one end the graph of the linear function

is a ray rather than a line

Module 1 11 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 11 11415 241 AM

ELABORATE INTEGRATE MATHEMATICAL PROCESSESFocus on CommunicationDiscuss different strategies for determining the range of a function from a graph of the function Have students describe methods they use and illustrate their methods using graphs of different types of functions including those with restricted domains

QUESTIONING STRATEGIESIs it possible that a real-world situation can be modeled by a function whose domain consists

of both positive and negative real numbers If no explain why not If yes give an example Yes

Possible example a function that describes the

relationship between air temperature in degrees

Fahrenheit and dew point at a given level of

humidity The domain consists of all possible air

temperatures in degrees Fahrenheit

SUMMARIZE THE LESSONHow do you identify and represent the domain range and end behavior of a

function To identify the domain find the values of

x for which the function is defined To find the

range find the values of f (x) for each value of x in

the domain There are different ways of

representing the domain and range including using

inequalities set notation and interval notation To

find the end-behavior consider what happens to

the values of the range as the values of the domain

increase or decrease without bound

11 Lesson 1 1

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

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0 42

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oughton Mifflin H

arcourt Publishing Company

bull Online Homeworkbull Hints and Helpbull Extra Practice

1 Write the interval shown on the number line as an inequality using set notation and using interval notation

2 Write the interval (5 100] as an inequality and using set notation

3 Write the interval -25 le x lt 30 using set notation and interval notation

4 Write the interval x| -3 lt x lt 5 as an inequality and using interval notation

Write the domain and the range of the function as an inequality using set notation and using interval notation Also describe the end behavior of the function or explain why there is no end behavior

5 The graph of the quadratic functionf (x) = x 2 + 2 is shown

6 The graph of the exponential function f (x) = 3 x is shown

Evaluate Homework and Practice

x ge 5 x|x ge 5 [5 +infin)

x| -25 le x lt 30 [-25 30)

5 lt x le 100 x|5 lt x le 100

-3 lt x lt 5 (-3 5)

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range 2 le y lt +infin y⎪ 2 le y lt +infin ⎡ ⎣ 2 +infin)End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr +infin

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range 0 lt y lt +infin y⎪ 0 lt y lt +infin (0 +infin)End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr 0

Module 1 12 Lesson 1

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-A

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-A

A2_MTXESE353930_U1M01L1indd 12 22214 304 AMExercise Depth of Knowledge (DOK) Mathematical Processes

1ndash8 1 Recall of Information 1F Analyze relationships

9ndash10 1 Recall of Information 1E Create and use representations

11 1 Recall of Information 1D Multiple representations

12 2 SkillsConcepts 1A Everyday life

13 2 SkillsConcepts 1G Explain and justify arguments

14 3 Strategic Thinking 1D Multiple representations

EVALUATE

ASSIGNMENT GUIDE

Concepts and Skills Practice

ExploreRepresenting an Interval on a Number Line

Exercise 1ndash4

Example 1Identifying a Functionrsquos Domain Range and End Behavior from its Graph

Exercises 5ndash8

Example 2Graphing a Linear Function on a Restricted Domain

Exercises 9ndash10

Example 3Modeling with a Linear Function

Exercises 11ndash12

VISUAL CUESSome students may benefit from labeling the endpoints of an interval as included or not included as indicated by the closed circle or open circle on the graph They will then be sure to use the appropriate symbols when describing the interval using the different types of notation

CONNECT VOCABULARY Relate end behavior to the shape of the graph of different functions Have students use words to describe the end behavior of each function by looking at the graph For example a function ƒ (x) appears to rise for positive x-values and fall for negative x-values

Domain Range and End Behavior 12

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

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0 42

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6

y

0 42

x

-2-4 -4

-2

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-2-4

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7 The graph of the linear function g (x) = 2x - 2 is shown

8 The graph of a function is shown

For the given function and domain draw the graph and identify the range using the same notation as the given domain

9 f(x) = minusx + 5 with domain [minus3 2] 10 f(x) = 3 _ 2 x + 1 with domain x |x gt minus 2

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range minusinfin lt y lt +infin y⎪ minusinfin lt y lt +infin (minusinfin +infin) End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr -infin

Domain minus4 le x le 4 x⎪ minus4 le x le 4 [minus4 4]

Range 0 le y le 4 y⎪ 0 le y le 4 [0 4]

There is no end behavior because the domain is bounded at both ends

Since f (x) = -x + 5 is a linear

function the graph is a line

segment with endpoints at

(-3 f (-3) ) or (minus3 8) and

(2 f(2)) or (2 3) The endpoints

are included in the graph

The range is [3 8]

Since f (x) = 3 _ 2

x + 1 is a linear

function the graph is a ray with

its endpoint at (-2 f (-2) )

or (minus2 minus2) The endpoint is not

included in the graph

The range is y⎪ y gt - 2

Module 1 13 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 13 11415 241 AMExercise Depth of Knowledge (DOK) Mathematical Processes

15 2 SkillsConcepts 1E Create and use representations

MULTIPLE REPRESENTATIONSWhen analyzing the graph of a function students may find it easier to first describe the end behavior of the function in words They then can translate their verbal descriptions into algebraic notation making sure that the symbols accurately reflect their descriptions

KINESTHETIC EXPERIENCETo help students correctly identify end behavior suggest that they use a finger to trace along the graph of a function moving first from left to right as x rarr infin and then from right to left as x rarr -infin Help them to match their observations of the behavior of the graph to its correct description and notation

13 Lesson 1 1

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

0

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1

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7

Time (h)D

ista

nce

trav

eled

(mi)

d

t

0402 0806

0

20

40

60

8090

10

30

50

70

Time (s)

Hei

ght a

bove

gro

und

(m) h

t

8642 7531

copy H

oug

hton Mifflin H

arcourt Publishin

g Com

pany bull Im

age C

redits copy

CaroA

lamy

Write a function that models the given situation Determine the domain from the situation graph the function using that domain and identify the range

11 A bicyclist travels at a constant speed of 12 miles per hour for a total of 45 minutes (Use set notation for the domain and range of the function that models this situation)

12 An elevator in a tall building starts at a floor of the building that is 90 meters above the ground The elevator descends 2 meters every 05 second for 6 seconds (Use an inequality for the domain and range of the function that models this situation)

HOT Focus on Higher Order Thinking

13 Explain the Error Cameron sells tickets at a movie theater On Friday night she worked from 4 pm to 10 pm and sold about 25 tickets every hour Cameron says that the number of tickets n she has sold at any time t (in hours) can be modeled by the function n(t) = 25t where the domain is 0 le t le 1 and the range is 0 le n le 25 Is Cameronrsquos function along with the domain and range correct Explain

The bicyclistrsquos speed is 12 mih The distance traveled

d (in miles) at any time t (in hours) is modeled by

d(t) = 12t Since the bicyclist travels for 45 minutes

or 075 hour the domain is restricted to the interval

t⎪0 le t le 075

The range is d⎪0 le d le 9

The elevatorrsquos rate of motion is -4 ms The elevatorrsquos

height h (in meters) at any time t (in seconds) is modeled by

h(t) = 90 - 4t Since the elevator descends for 6 seconds

the domain is restricted to the interval 0 le t le 6

The range is 66 le h le 90

Cameronrsquos function is correct but the domain and range are incorrect Cameron worked for a total of 6 hours so the domain of the function should be 0 le t le 6 After 6 hours Cameron has sold 25 times 6 = 150 tickets So the range of the function should be 0 le n le 150

Module 1 14 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 14 11415 241 AM

QUESTIONING STRATEGIESWhen is the graph of a linear function with a restricted domain a line segment When is it a

ray It is a line segment when the domain is a

closed interval It is a ray when the domain is

restricted to real numbers greater than or equal to a

number or less than or equal to a number

AVOID COMMON ERRORSWhen attempting to model a real-world situation students sometimes confuse the dependent and independent variables thus reversing the domain and range Help them to understand that the domain consists of the values represented by the independent variable and that the range values are a function of the values of the domain

Domain Range and End Behavior 14

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

y

x2 4-4

100

50

-100

-50

0

y

x2 4-4

100

50

-100

-50

0

0

200

400

600

800

Distance from tower (ft)

Hei

ght a

bove

bri

dge

deck

(ft)

y

x

400200 800 1000600

copy H

oug

hton

Mif

flin

Har

cour

t Pub

lishi

ng

Com

pan

y

14 Multi-Step The graph of the cubic function ƒ(x) = x 3 is shown

a What are the domain range and end behavior of the function (Write the domain and range as an inequality using set notation and using interval notation)

b How is the range of the function affected if the domain is restricted to [-4 4] (Write the range as an inequality using set notation and using interval notation)

c Graph the function with the restricted domain

15 Represent Real-World Situations The John James Audubon Bridge is a cable-stayed bridge in Louisiana that opened in 2011 The height from the bridge deck to the top of the tower where a particular cable is anchored is about 500 feet and the length of that cable is about 1200 feet Draw the cable on a coordinate plane letting the x-axis represent the bridge deck and the y-axis represent the tower (Only use positive values of x and y) Write a linear function whose graph models the cable Identify the domain and range writing each as an inequality using set notation and using interval notation

a Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range minusinfin lt y lt +infin y⎪ minusinfin lt y lt +infin (minusinfin +infin) End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr -infin

b Restricted range -64 le y le 64 y⎪ minus64 le y le +64 [-64 64]

c

Since the cable the bridge deck and the

tower form a right triangle find the length

of the leg that lies on the x-axis by using the

Pythagorean Theorem

a 2 + b 2 = c 2

500 2 + b 2 = 1200 2

b asymp 109 1

slope m = 500 - 0 _ 0 - 1091

= 500 _ -1091 asymp -046

The y-intercept is 500

So the linear function is y = -046x + 500

Domain 0 le x le 1091 x⎪0 le x le 1091 [0 1091]

Range 0 le y le 500 y⎪0 le y le 500 [0 500]

Module 1 15 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 15 11415 241 AM

PEERTOPEER DISCUSSIONIs it possible that a linear function with the domain all real numbers could have a range that is not all real numbers Explain Yes the function could be a

constant function such as f (x) = 2 The domain is

all real numbers but the range is 2

You may want to have students work on the modeling questions in pairs thus providing them with an opportunity to discuss each situation with a partner and decide how to best model the situation using a function

JOURNALHave students describe how to identify the domain and range of a function given its graph or given the situation it models

15 Lesson 1 1

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

0

100

200

300

400450500550

50

150

250

350

Gas used (gal)

Dis

tanc

e tr

avel

ed (m

i)

d

g

161284

20122007

copy H

oug

hton Mifflin H

arcourt Publishin

g Com

pany

The fuel efficiency for a 2007 passenger car was 312 migal For the same model of car the fuel efficiency increased to 356 migal in 2012 The gas tank for this car holds 16 gallons of gas

a Write and graph a linear function that models the distance that each car can travel for a given amount of gas (up to one tankful)

b Write the domain and range of each function using interval notation

c Write and simplify a function ƒ (g) that represents the difference in the distance that the 2012 car can travel and the distance that the 2007 car can travel on the same amount of gas Interpret this function using the graphs of the functions from part a Also find and interpret ƒ (16)

d Write the domain and range of the difference function using set notation

Lesson Performance Task

a For both cars let g be the amount of gas (in gallons) that each car uses and let d be the distance (in miles) that each car travels For the 2007 car the linear model is d 2007 (g) = 312g For the 2012 car the linear model is d 2012 (g) = 356g

b The domain for the 2007 model is [0 16] and the range is [0 4992] The domain for the 2012 model is [0 16] and the range is [0 5696]

c The difference function is f(g) = d 2012 (g) minus d 2007 (g) = 356g minus 312g = 44g This function gives the vertical distance between the graphs of d 2012 (g) and d 2007 (g) For instance when g = 16 the vertical distance between the graphs is f(16) = 44 16 = 704 which means the 2012 car can travel 704 miles farther on a tankful of gas than the 2007 car

d The domain is g⎪0 le g le 16 and the range is f(g)⎪0 le f(g) le 704

Module 1 16 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-A

A2_MTXESE353930_U1M01L1indd 16 22214 319 AM

EXTENSION ACTIVITY

Have students research the average fuel costs per gallon in 2007 and in 2012 Have students use the data to create a new graph representing the distance each car could travel for a given amount of money (up to the cost of a typical full tank) Ask students to describe the aspects of their graphs

QUESTIONING STRATEGIESWhy must restrictions be placed on the domain The tank only holds at most 16

gallons of gas and at least 0 gallons of gas A graph

with a negative number of gallons of gas or more

than 16 gallons of gas would not make sense for

this situation

Why does the domain contain all of the points in the interval and not just the integer

values The amount of gas used is continuous

There is a distance traveled for any value of g in

the domain

INTEGRATE MATHEMATICAL PROCESSESFocus on CommunicationEncourage students to relate the ranges that they wrote for the difference functions to their graphs Have them determine whether the values in the range make sense in the real-world situation Then have students explain whether it makes sense that as the number of gallons used increases the difference in miles traveled by the two cars also increases

Scoring Rubric2 points Student correctly solves the problem and explains hisher reasoning1 point Student shows good understanding of the problem but does not fully solve or explain hisher reasoning0 points Student does not demonstrate understanding of the problem

Domain Range and End Behavior 16

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

Page 8: CorrectionKey=TX-A CorrectionKey=TX-B LESSON 1 . 1 …€¦ ·  · 2017-01-05A2.7.1 Write the domain and range of a function in interval notation, inequalities, and set notation

4

6

2

y

0 42

x

-2-4

12

18

24

6

y

0 42

x

-2-4

3 4 5 6 7 8

copy H

oughton Mifflin H

arcourt Publishing Company

bull Online Homeworkbull Hints and Helpbull Extra Practice

1 Write the interval shown on the number line as an inequality using set notation and using interval notation

2 Write the interval (5 100] as an inequality and using set notation

3 Write the interval -25 le x lt 30 using set notation and interval notation

4 Write the interval x| -3 lt x lt 5 as an inequality and using interval notation

Write the domain and the range of the function as an inequality using set notation and using interval notation Also describe the end behavior of the function or explain why there is no end behavior

5 The graph of the quadratic functionf (x) = x 2 + 2 is shown

6 The graph of the exponential function f (x) = 3 x is shown

Evaluate Homework and Practice

x ge 5 x|x ge 5 [5 +infin)

x| -25 le x lt 30 [-25 30)

5 lt x le 100 x|5 lt x le 100

-3 lt x lt 5 (-3 5)

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range 2 le y lt +infin y⎪ 2 le y lt +infin ⎡ ⎣ 2 +infin)End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr +infin

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range 0 lt y lt +infin y⎪ 0 lt y lt +infin (0 +infin)End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr 0

Module 1 12 Lesson 1

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-A

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-A

A2_MTXESE353930_U1M01L1indd 12 22214 304 AMExercise Depth of Knowledge (DOK) Mathematical Processes

1ndash8 1 Recall of Information 1F Analyze relationships

9ndash10 1 Recall of Information 1E Create and use representations

11 1 Recall of Information 1D Multiple representations

12 2 SkillsConcepts 1A Everyday life

13 2 SkillsConcepts 1G Explain and justify arguments

14 3 Strategic Thinking 1D Multiple representations

EVALUATE

ASSIGNMENT GUIDE

Concepts and Skills Practice

ExploreRepresenting an Interval on a Number Line

Exercise 1ndash4

Example 1Identifying a Functionrsquos Domain Range and End Behavior from its Graph

Exercises 5ndash8

Example 2Graphing a Linear Function on a Restricted Domain

Exercises 9ndash10

Example 3Modeling with a Linear Function

Exercises 11ndash12

VISUAL CUESSome students may benefit from labeling the endpoints of an interval as included or not included as indicated by the closed circle or open circle on the graph They will then be sure to use the appropriate symbols when describing the interval using the different types of notation

CONNECT VOCABULARY Relate end behavior to the shape of the graph of different functions Have students use words to describe the end behavior of each function by looking at the graph For example a function ƒ (x) appears to rise for positive x-values and fall for negative x-values

Domain Range and End Behavior 12

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

-2

4

2

y

0 42

x

-2-4-2

-4

2

y

0 42

x

-2-4

4

2

8

6

y

0 42

x

-2-4 -4

-2

4

2

y

0 42

x

-2-4

copy H

oug

hton

Mif

flin

Har

cour

t Pub

lishi

ng

Com

pan

y

7 The graph of the linear function g (x) = 2x - 2 is shown

8 The graph of a function is shown

For the given function and domain draw the graph and identify the range using the same notation as the given domain

9 f(x) = minusx + 5 with domain [minus3 2] 10 f(x) = 3 _ 2 x + 1 with domain x |x gt minus 2

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range minusinfin lt y lt +infin y⎪ minusinfin lt y lt +infin (minusinfin +infin) End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr -infin

Domain minus4 le x le 4 x⎪ minus4 le x le 4 [minus4 4]

Range 0 le y le 4 y⎪ 0 le y le 4 [0 4]

There is no end behavior because the domain is bounded at both ends

Since f (x) = -x + 5 is a linear

function the graph is a line

segment with endpoints at

(-3 f (-3) ) or (minus3 8) and

(2 f(2)) or (2 3) The endpoints

are included in the graph

The range is [3 8]

Since f (x) = 3 _ 2

x + 1 is a linear

function the graph is a ray with

its endpoint at (-2 f (-2) )

or (minus2 minus2) The endpoint is not

included in the graph

The range is y⎪ y gt - 2

Module 1 13 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 13 11415 241 AMExercise Depth of Knowledge (DOK) Mathematical Processes

15 2 SkillsConcepts 1E Create and use representations

MULTIPLE REPRESENTATIONSWhen analyzing the graph of a function students may find it easier to first describe the end behavior of the function in words They then can translate their verbal descriptions into algebraic notation making sure that the symbols accurately reflect their descriptions

KINESTHETIC EXPERIENCETo help students correctly identify end behavior suggest that they use a finger to trace along the graph of a function moving first from left to right as x rarr infin and then from right to left as x rarr -infin Help them to match their observations of the behavior of the graph to its correct description and notation

13 Lesson 1 1

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

0

2

4

6

89

1

3

5

7

Time (h)D

ista

nce

trav

eled

(mi)

d

t

0402 0806

0

20

40

60

8090

10

30

50

70

Time (s)

Hei

ght a

bove

gro

und

(m) h

t

8642 7531

copy H

oug

hton Mifflin H

arcourt Publishin

g Com

pany bull Im

age C

redits copy

CaroA

lamy

Write a function that models the given situation Determine the domain from the situation graph the function using that domain and identify the range

11 A bicyclist travels at a constant speed of 12 miles per hour for a total of 45 minutes (Use set notation for the domain and range of the function that models this situation)

12 An elevator in a tall building starts at a floor of the building that is 90 meters above the ground The elevator descends 2 meters every 05 second for 6 seconds (Use an inequality for the domain and range of the function that models this situation)

HOT Focus on Higher Order Thinking

13 Explain the Error Cameron sells tickets at a movie theater On Friday night she worked from 4 pm to 10 pm and sold about 25 tickets every hour Cameron says that the number of tickets n she has sold at any time t (in hours) can be modeled by the function n(t) = 25t where the domain is 0 le t le 1 and the range is 0 le n le 25 Is Cameronrsquos function along with the domain and range correct Explain

The bicyclistrsquos speed is 12 mih The distance traveled

d (in miles) at any time t (in hours) is modeled by

d(t) = 12t Since the bicyclist travels for 45 minutes

or 075 hour the domain is restricted to the interval

t⎪0 le t le 075

The range is d⎪0 le d le 9

The elevatorrsquos rate of motion is -4 ms The elevatorrsquos

height h (in meters) at any time t (in seconds) is modeled by

h(t) = 90 - 4t Since the elevator descends for 6 seconds

the domain is restricted to the interval 0 le t le 6

The range is 66 le h le 90

Cameronrsquos function is correct but the domain and range are incorrect Cameron worked for a total of 6 hours so the domain of the function should be 0 le t le 6 After 6 hours Cameron has sold 25 times 6 = 150 tickets So the range of the function should be 0 le n le 150

Module 1 14 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 14 11415 241 AM

QUESTIONING STRATEGIESWhen is the graph of a linear function with a restricted domain a line segment When is it a

ray It is a line segment when the domain is a

closed interval It is a ray when the domain is

restricted to real numbers greater than or equal to a

number or less than or equal to a number

AVOID COMMON ERRORSWhen attempting to model a real-world situation students sometimes confuse the dependent and independent variables thus reversing the domain and range Help them to understand that the domain consists of the values represented by the independent variable and that the range values are a function of the values of the domain

Domain Range and End Behavior 14

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

y

x2 4-4

100

50

-100

-50

0

y

x2 4-4

100

50

-100

-50

0

0

200

400

600

800

Distance from tower (ft)

Hei

ght a

bove

bri

dge

deck

(ft)

y

x

400200 800 1000600

copy H

oug

hton

Mif

flin

Har

cour

t Pub

lishi

ng

Com

pan

y

14 Multi-Step The graph of the cubic function ƒ(x) = x 3 is shown

a What are the domain range and end behavior of the function (Write the domain and range as an inequality using set notation and using interval notation)

b How is the range of the function affected if the domain is restricted to [-4 4] (Write the range as an inequality using set notation and using interval notation)

c Graph the function with the restricted domain

15 Represent Real-World Situations The John James Audubon Bridge is a cable-stayed bridge in Louisiana that opened in 2011 The height from the bridge deck to the top of the tower where a particular cable is anchored is about 500 feet and the length of that cable is about 1200 feet Draw the cable on a coordinate plane letting the x-axis represent the bridge deck and the y-axis represent the tower (Only use positive values of x and y) Write a linear function whose graph models the cable Identify the domain and range writing each as an inequality using set notation and using interval notation

a Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range minusinfin lt y lt +infin y⎪ minusinfin lt y lt +infin (minusinfin +infin) End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr -infin

b Restricted range -64 le y le 64 y⎪ minus64 le y le +64 [-64 64]

c

Since the cable the bridge deck and the

tower form a right triangle find the length

of the leg that lies on the x-axis by using the

Pythagorean Theorem

a 2 + b 2 = c 2

500 2 + b 2 = 1200 2

b asymp 109 1

slope m = 500 - 0 _ 0 - 1091

= 500 _ -1091 asymp -046

The y-intercept is 500

So the linear function is y = -046x + 500

Domain 0 le x le 1091 x⎪0 le x le 1091 [0 1091]

Range 0 le y le 500 y⎪0 le y le 500 [0 500]

Module 1 15 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 15 11415 241 AM

PEERTOPEER DISCUSSIONIs it possible that a linear function with the domain all real numbers could have a range that is not all real numbers Explain Yes the function could be a

constant function such as f (x) = 2 The domain is

all real numbers but the range is 2

You may want to have students work on the modeling questions in pairs thus providing them with an opportunity to discuss each situation with a partner and decide how to best model the situation using a function

JOURNALHave students describe how to identify the domain and range of a function given its graph or given the situation it models

15 Lesson 1 1

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

0

100

200

300

400450500550

50

150

250

350

Gas used (gal)

Dis

tanc

e tr

avel

ed (m

i)

d

g

161284

20122007

copy H

oug

hton Mifflin H

arcourt Publishin

g Com

pany

The fuel efficiency for a 2007 passenger car was 312 migal For the same model of car the fuel efficiency increased to 356 migal in 2012 The gas tank for this car holds 16 gallons of gas

a Write and graph a linear function that models the distance that each car can travel for a given amount of gas (up to one tankful)

b Write the domain and range of each function using interval notation

c Write and simplify a function ƒ (g) that represents the difference in the distance that the 2012 car can travel and the distance that the 2007 car can travel on the same amount of gas Interpret this function using the graphs of the functions from part a Also find and interpret ƒ (16)

d Write the domain and range of the difference function using set notation

Lesson Performance Task

a For both cars let g be the amount of gas (in gallons) that each car uses and let d be the distance (in miles) that each car travels For the 2007 car the linear model is d 2007 (g) = 312g For the 2012 car the linear model is d 2012 (g) = 356g

b The domain for the 2007 model is [0 16] and the range is [0 4992] The domain for the 2012 model is [0 16] and the range is [0 5696]

c The difference function is f(g) = d 2012 (g) minus d 2007 (g) = 356g minus 312g = 44g This function gives the vertical distance between the graphs of d 2012 (g) and d 2007 (g) For instance when g = 16 the vertical distance between the graphs is f(16) = 44 16 = 704 which means the 2012 car can travel 704 miles farther on a tankful of gas than the 2007 car

d The domain is g⎪0 le g le 16 and the range is f(g)⎪0 le f(g) le 704

Module 1 16 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-A

A2_MTXESE353930_U1M01L1indd 16 22214 319 AM

EXTENSION ACTIVITY

Have students research the average fuel costs per gallon in 2007 and in 2012 Have students use the data to create a new graph representing the distance each car could travel for a given amount of money (up to the cost of a typical full tank) Ask students to describe the aspects of their graphs

QUESTIONING STRATEGIESWhy must restrictions be placed on the domain The tank only holds at most 16

gallons of gas and at least 0 gallons of gas A graph

with a negative number of gallons of gas or more

than 16 gallons of gas would not make sense for

this situation

Why does the domain contain all of the points in the interval and not just the integer

values The amount of gas used is continuous

There is a distance traveled for any value of g in

the domain

INTEGRATE MATHEMATICAL PROCESSESFocus on CommunicationEncourage students to relate the ranges that they wrote for the difference functions to their graphs Have them determine whether the values in the range make sense in the real-world situation Then have students explain whether it makes sense that as the number of gallons used increases the difference in miles traveled by the two cars also increases

Scoring Rubric2 points Student correctly solves the problem and explains hisher reasoning1 point Student shows good understanding of the problem but does not fully solve or explain hisher reasoning0 points Student does not demonstrate understanding of the problem

Domain Range and End Behavior 16

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

Page 9: CorrectionKey=TX-A CorrectionKey=TX-B LESSON 1 . 1 …€¦ ·  · 2017-01-05A2.7.1 Write the domain and range of a function in interval notation, inequalities, and set notation

-2

4

2

y

0 42

x

-2-4-2

-4

2

y

0 42

x

-2-4

4

2

8

6

y

0 42

x

-2-4 -4

-2

4

2

y

0 42

x

-2-4

copy H

oug

hton

Mif

flin

Har

cour

t Pub

lishi

ng

Com

pan

y

7 The graph of the linear function g (x) = 2x - 2 is shown

8 The graph of a function is shown

For the given function and domain draw the graph and identify the range using the same notation as the given domain

9 f(x) = minusx + 5 with domain [minus3 2] 10 f(x) = 3 _ 2 x + 1 with domain x |x gt minus 2

Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range minusinfin lt y lt +infin y⎪ minusinfin lt y lt +infin (minusinfin +infin) End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr -infin

Domain minus4 le x le 4 x⎪ minus4 le x le 4 [minus4 4]

Range 0 le y le 4 y⎪ 0 le y le 4 [0 4]

There is no end behavior because the domain is bounded at both ends

Since f (x) = -x + 5 is a linear

function the graph is a line

segment with endpoints at

(-3 f (-3) ) or (minus3 8) and

(2 f(2)) or (2 3) The endpoints

are included in the graph

The range is [3 8]

Since f (x) = 3 _ 2

x + 1 is a linear

function the graph is a ray with

its endpoint at (-2 f (-2) )

or (minus2 minus2) The endpoint is not

included in the graph

The range is y⎪ y gt - 2

Module 1 13 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 13 11415 241 AMExercise Depth of Knowledge (DOK) Mathematical Processes

15 2 SkillsConcepts 1E Create and use representations

MULTIPLE REPRESENTATIONSWhen analyzing the graph of a function students may find it easier to first describe the end behavior of the function in words They then can translate their verbal descriptions into algebraic notation making sure that the symbols accurately reflect their descriptions

KINESTHETIC EXPERIENCETo help students correctly identify end behavior suggest that they use a finger to trace along the graph of a function moving first from left to right as x rarr infin and then from right to left as x rarr -infin Help them to match their observations of the behavior of the graph to its correct description and notation

13 Lesson 1 1

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

0

2

4

6

89

1

3

5

7

Time (h)D

ista

nce

trav

eled

(mi)

d

t

0402 0806

0

20

40

60

8090

10

30

50

70

Time (s)

Hei

ght a

bove

gro

und

(m) h

t

8642 7531

copy H

oug

hton Mifflin H

arcourt Publishin

g Com

pany bull Im

age C

redits copy

CaroA

lamy

Write a function that models the given situation Determine the domain from the situation graph the function using that domain and identify the range

11 A bicyclist travels at a constant speed of 12 miles per hour for a total of 45 minutes (Use set notation for the domain and range of the function that models this situation)

12 An elevator in a tall building starts at a floor of the building that is 90 meters above the ground The elevator descends 2 meters every 05 second for 6 seconds (Use an inequality for the domain and range of the function that models this situation)

HOT Focus on Higher Order Thinking

13 Explain the Error Cameron sells tickets at a movie theater On Friday night she worked from 4 pm to 10 pm and sold about 25 tickets every hour Cameron says that the number of tickets n she has sold at any time t (in hours) can be modeled by the function n(t) = 25t where the domain is 0 le t le 1 and the range is 0 le n le 25 Is Cameronrsquos function along with the domain and range correct Explain

The bicyclistrsquos speed is 12 mih The distance traveled

d (in miles) at any time t (in hours) is modeled by

d(t) = 12t Since the bicyclist travels for 45 minutes

or 075 hour the domain is restricted to the interval

t⎪0 le t le 075

The range is d⎪0 le d le 9

The elevatorrsquos rate of motion is -4 ms The elevatorrsquos

height h (in meters) at any time t (in seconds) is modeled by

h(t) = 90 - 4t Since the elevator descends for 6 seconds

the domain is restricted to the interval 0 le t le 6

The range is 66 le h le 90

Cameronrsquos function is correct but the domain and range are incorrect Cameron worked for a total of 6 hours so the domain of the function should be 0 le t le 6 After 6 hours Cameron has sold 25 times 6 = 150 tickets So the range of the function should be 0 le n le 150

Module 1 14 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 14 11415 241 AM

QUESTIONING STRATEGIESWhen is the graph of a linear function with a restricted domain a line segment When is it a

ray It is a line segment when the domain is a

closed interval It is a ray when the domain is

restricted to real numbers greater than or equal to a

number or less than or equal to a number

AVOID COMMON ERRORSWhen attempting to model a real-world situation students sometimes confuse the dependent and independent variables thus reversing the domain and range Help them to understand that the domain consists of the values represented by the independent variable and that the range values are a function of the values of the domain

Domain Range and End Behavior 14

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

y

x2 4-4

100

50

-100

-50

0

y

x2 4-4

100

50

-100

-50

0

0

200

400

600

800

Distance from tower (ft)

Hei

ght a

bove

bri

dge

deck

(ft)

y

x

400200 800 1000600

copy H

oug

hton

Mif

flin

Har

cour

t Pub

lishi

ng

Com

pan

y

14 Multi-Step The graph of the cubic function ƒ(x) = x 3 is shown

a What are the domain range and end behavior of the function (Write the domain and range as an inequality using set notation and using interval notation)

b How is the range of the function affected if the domain is restricted to [-4 4] (Write the range as an inequality using set notation and using interval notation)

c Graph the function with the restricted domain

15 Represent Real-World Situations The John James Audubon Bridge is a cable-stayed bridge in Louisiana that opened in 2011 The height from the bridge deck to the top of the tower where a particular cable is anchored is about 500 feet and the length of that cable is about 1200 feet Draw the cable on a coordinate plane letting the x-axis represent the bridge deck and the y-axis represent the tower (Only use positive values of x and y) Write a linear function whose graph models the cable Identify the domain and range writing each as an inequality using set notation and using interval notation

a Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range minusinfin lt y lt +infin y⎪ minusinfin lt y lt +infin (minusinfin +infin) End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr -infin

b Restricted range -64 le y le 64 y⎪ minus64 le y le +64 [-64 64]

c

Since the cable the bridge deck and the

tower form a right triangle find the length

of the leg that lies on the x-axis by using the

Pythagorean Theorem

a 2 + b 2 = c 2

500 2 + b 2 = 1200 2

b asymp 109 1

slope m = 500 - 0 _ 0 - 1091

= 500 _ -1091 asymp -046

The y-intercept is 500

So the linear function is y = -046x + 500

Domain 0 le x le 1091 x⎪0 le x le 1091 [0 1091]

Range 0 le y le 500 y⎪0 le y le 500 [0 500]

Module 1 15 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 15 11415 241 AM

PEERTOPEER DISCUSSIONIs it possible that a linear function with the domain all real numbers could have a range that is not all real numbers Explain Yes the function could be a

constant function such as f (x) = 2 The domain is

all real numbers but the range is 2

You may want to have students work on the modeling questions in pairs thus providing them with an opportunity to discuss each situation with a partner and decide how to best model the situation using a function

JOURNALHave students describe how to identify the domain and range of a function given its graph or given the situation it models

15 Lesson 1 1

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

0

100

200

300

400450500550

50

150

250

350

Gas used (gal)

Dis

tanc

e tr

avel

ed (m

i)

d

g

161284

20122007

copy H

oug

hton Mifflin H

arcourt Publishin

g Com

pany

The fuel efficiency for a 2007 passenger car was 312 migal For the same model of car the fuel efficiency increased to 356 migal in 2012 The gas tank for this car holds 16 gallons of gas

a Write and graph a linear function that models the distance that each car can travel for a given amount of gas (up to one tankful)

b Write the domain and range of each function using interval notation

c Write and simplify a function ƒ (g) that represents the difference in the distance that the 2012 car can travel and the distance that the 2007 car can travel on the same amount of gas Interpret this function using the graphs of the functions from part a Also find and interpret ƒ (16)

d Write the domain and range of the difference function using set notation

Lesson Performance Task

a For both cars let g be the amount of gas (in gallons) that each car uses and let d be the distance (in miles) that each car travels For the 2007 car the linear model is d 2007 (g) = 312g For the 2012 car the linear model is d 2012 (g) = 356g

b The domain for the 2007 model is [0 16] and the range is [0 4992] The domain for the 2012 model is [0 16] and the range is [0 5696]

c The difference function is f(g) = d 2012 (g) minus d 2007 (g) = 356g minus 312g = 44g This function gives the vertical distance between the graphs of d 2012 (g) and d 2007 (g) For instance when g = 16 the vertical distance between the graphs is f(16) = 44 16 = 704 which means the 2012 car can travel 704 miles farther on a tankful of gas than the 2007 car

d The domain is g⎪0 le g le 16 and the range is f(g)⎪0 le f(g) le 704

Module 1 16 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-A

A2_MTXESE353930_U1M01L1indd 16 22214 319 AM

EXTENSION ACTIVITY

Have students research the average fuel costs per gallon in 2007 and in 2012 Have students use the data to create a new graph representing the distance each car could travel for a given amount of money (up to the cost of a typical full tank) Ask students to describe the aspects of their graphs

QUESTIONING STRATEGIESWhy must restrictions be placed on the domain The tank only holds at most 16

gallons of gas and at least 0 gallons of gas A graph

with a negative number of gallons of gas or more

than 16 gallons of gas would not make sense for

this situation

Why does the domain contain all of the points in the interval and not just the integer

values The amount of gas used is continuous

There is a distance traveled for any value of g in

the domain

INTEGRATE MATHEMATICAL PROCESSESFocus on CommunicationEncourage students to relate the ranges that they wrote for the difference functions to their graphs Have them determine whether the values in the range make sense in the real-world situation Then have students explain whether it makes sense that as the number of gallons used increases the difference in miles traveled by the two cars also increases

Scoring Rubric2 points Student correctly solves the problem and explains hisher reasoning1 point Student shows good understanding of the problem but does not fully solve or explain hisher reasoning0 points Student does not demonstrate understanding of the problem

Domain Range and End Behavior 16

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

Page 10: CorrectionKey=TX-A CorrectionKey=TX-B LESSON 1 . 1 …€¦ ·  · 2017-01-05A2.7.1 Write the domain and range of a function in interval notation, inequalities, and set notation

0

2

4

6

89

1

3

5

7

Time (h)D

ista

nce

trav

eled

(mi)

d

t

0402 0806

0

20

40

60

8090

10

30

50

70

Time (s)

Hei

ght a

bove

gro

und

(m) h

t

8642 7531

copy H

oug

hton Mifflin H

arcourt Publishin

g Com

pany bull Im

age C

redits copy

CaroA

lamy

Write a function that models the given situation Determine the domain from the situation graph the function using that domain and identify the range

11 A bicyclist travels at a constant speed of 12 miles per hour for a total of 45 minutes (Use set notation for the domain and range of the function that models this situation)

12 An elevator in a tall building starts at a floor of the building that is 90 meters above the ground The elevator descends 2 meters every 05 second for 6 seconds (Use an inequality for the domain and range of the function that models this situation)

HOT Focus on Higher Order Thinking

13 Explain the Error Cameron sells tickets at a movie theater On Friday night she worked from 4 pm to 10 pm and sold about 25 tickets every hour Cameron says that the number of tickets n she has sold at any time t (in hours) can be modeled by the function n(t) = 25t where the domain is 0 le t le 1 and the range is 0 le n le 25 Is Cameronrsquos function along with the domain and range correct Explain

The bicyclistrsquos speed is 12 mih The distance traveled

d (in miles) at any time t (in hours) is modeled by

d(t) = 12t Since the bicyclist travels for 45 minutes

or 075 hour the domain is restricted to the interval

t⎪0 le t le 075

The range is d⎪0 le d le 9

The elevatorrsquos rate of motion is -4 ms The elevatorrsquos

height h (in meters) at any time t (in seconds) is modeled by

h(t) = 90 - 4t Since the elevator descends for 6 seconds

the domain is restricted to the interval 0 le t le 6

The range is 66 le h le 90

Cameronrsquos function is correct but the domain and range are incorrect Cameron worked for a total of 6 hours so the domain of the function should be 0 le t le 6 After 6 hours Cameron has sold 25 times 6 = 150 tickets So the range of the function should be 0 le n le 150

Module 1 14 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 14 11415 241 AM

QUESTIONING STRATEGIESWhen is the graph of a linear function with a restricted domain a line segment When is it a

ray It is a line segment when the domain is a

closed interval It is a ray when the domain is

restricted to real numbers greater than or equal to a

number or less than or equal to a number

AVOID COMMON ERRORSWhen attempting to model a real-world situation students sometimes confuse the dependent and independent variables thus reversing the domain and range Help them to understand that the domain consists of the values represented by the independent variable and that the range values are a function of the values of the domain

Domain Range and End Behavior 14

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

y

x2 4-4

100

50

-100

-50

0

y

x2 4-4

100

50

-100

-50

0

0

200

400

600

800

Distance from tower (ft)

Hei

ght a

bove

bri

dge

deck

(ft)

y

x

400200 800 1000600

copy H

oug

hton

Mif

flin

Har

cour

t Pub

lishi

ng

Com

pan

y

14 Multi-Step The graph of the cubic function ƒ(x) = x 3 is shown

a What are the domain range and end behavior of the function (Write the domain and range as an inequality using set notation and using interval notation)

b How is the range of the function affected if the domain is restricted to [-4 4] (Write the range as an inequality using set notation and using interval notation)

c Graph the function with the restricted domain

15 Represent Real-World Situations The John James Audubon Bridge is a cable-stayed bridge in Louisiana that opened in 2011 The height from the bridge deck to the top of the tower where a particular cable is anchored is about 500 feet and the length of that cable is about 1200 feet Draw the cable on a coordinate plane letting the x-axis represent the bridge deck and the y-axis represent the tower (Only use positive values of x and y) Write a linear function whose graph models the cable Identify the domain and range writing each as an inequality using set notation and using interval notation

a Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range minusinfin lt y lt +infin y⎪ minusinfin lt y lt +infin (minusinfin +infin) End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr -infin

b Restricted range -64 le y le 64 y⎪ minus64 le y le +64 [-64 64]

c

Since the cable the bridge deck and the

tower form a right triangle find the length

of the leg that lies on the x-axis by using the

Pythagorean Theorem

a 2 + b 2 = c 2

500 2 + b 2 = 1200 2

b asymp 109 1

slope m = 500 - 0 _ 0 - 1091

= 500 _ -1091 asymp -046

The y-intercept is 500

So the linear function is y = -046x + 500

Domain 0 le x le 1091 x⎪0 le x le 1091 [0 1091]

Range 0 le y le 500 y⎪0 le y le 500 [0 500]

Module 1 15 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 15 11415 241 AM

PEERTOPEER DISCUSSIONIs it possible that a linear function with the domain all real numbers could have a range that is not all real numbers Explain Yes the function could be a

constant function such as f (x) = 2 The domain is

all real numbers but the range is 2

You may want to have students work on the modeling questions in pairs thus providing them with an opportunity to discuss each situation with a partner and decide how to best model the situation using a function

JOURNALHave students describe how to identify the domain and range of a function given its graph or given the situation it models

15 Lesson 1 1

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

0

100

200

300

400450500550

50

150

250

350

Gas used (gal)

Dis

tanc

e tr

avel

ed (m

i)

d

g

161284

20122007

copy H

oug

hton Mifflin H

arcourt Publishin

g Com

pany

The fuel efficiency for a 2007 passenger car was 312 migal For the same model of car the fuel efficiency increased to 356 migal in 2012 The gas tank for this car holds 16 gallons of gas

a Write and graph a linear function that models the distance that each car can travel for a given amount of gas (up to one tankful)

b Write the domain and range of each function using interval notation

c Write and simplify a function ƒ (g) that represents the difference in the distance that the 2012 car can travel and the distance that the 2007 car can travel on the same amount of gas Interpret this function using the graphs of the functions from part a Also find and interpret ƒ (16)

d Write the domain and range of the difference function using set notation

Lesson Performance Task

a For both cars let g be the amount of gas (in gallons) that each car uses and let d be the distance (in miles) that each car travels For the 2007 car the linear model is d 2007 (g) = 312g For the 2012 car the linear model is d 2012 (g) = 356g

b The domain for the 2007 model is [0 16] and the range is [0 4992] The domain for the 2012 model is [0 16] and the range is [0 5696]

c The difference function is f(g) = d 2012 (g) minus d 2007 (g) = 356g minus 312g = 44g This function gives the vertical distance between the graphs of d 2012 (g) and d 2007 (g) For instance when g = 16 the vertical distance between the graphs is f(16) = 44 16 = 704 which means the 2012 car can travel 704 miles farther on a tankful of gas than the 2007 car

d The domain is g⎪0 le g le 16 and the range is f(g)⎪0 le f(g) le 704

Module 1 16 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-A

A2_MTXESE353930_U1M01L1indd 16 22214 319 AM

EXTENSION ACTIVITY

Have students research the average fuel costs per gallon in 2007 and in 2012 Have students use the data to create a new graph representing the distance each car could travel for a given amount of money (up to the cost of a typical full tank) Ask students to describe the aspects of their graphs

QUESTIONING STRATEGIESWhy must restrictions be placed on the domain The tank only holds at most 16

gallons of gas and at least 0 gallons of gas A graph

with a negative number of gallons of gas or more

than 16 gallons of gas would not make sense for

this situation

Why does the domain contain all of the points in the interval and not just the integer

values The amount of gas used is continuous

There is a distance traveled for any value of g in

the domain

INTEGRATE MATHEMATICAL PROCESSESFocus on CommunicationEncourage students to relate the ranges that they wrote for the difference functions to their graphs Have them determine whether the values in the range make sense in the real-world situation Then have students explain whether it makes sense that as the number of gallons used increases the difference in miles traveled by the two cars also increases

Scoring Rubric2 points Student correctly solves the problem and explains hisher reasoning1 point Student shows good understanding of the problem but does not fully solve or explain hisher reasoning0 points Student does not demonstrate understanding of the problem

Domain Range and End Behavior 16

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

Page 11: CorrectionKey=TX-A CorrectionKey=TX-B LESSON 1 . 1 …€¦ ·  · 2017-01-05A2.7.1 Write the domain and range of a function in interval notation, inequalities, and set notation

y

x2 4-4

100

50

-100

-50

0

y

x2 4-4

100

50

-100

-50

0

0

200

400

600

800

Distance from tower (ft)

Hei

ght a

bove

bri

dge

deck

(ft)

y

x

400200 800 1000600

copy H

oug

hton

Mif

flin

Har

cour

t Pub

lishi

ng

Com

pan

y

14 Multi-Step The graph of the cubic function ƒ(x) = x 3 is shown

a What are the domain range and end behavior of the function (Write the domain and range as an inequality using set notation and using interval notation)

b How is the range of the function affected if the domain is restricted to [-4 4] (Write the range as an inequality using set notation and using interval notation)

c Graph the function with the restricted domain

15 Represent Real-World Situations The John James Audubon Bridge is a cable-stayed bridge in Louisiana that opened in 2011 The height from the bridge deck to the top of the tower where a particular cable is anchored is about 500 feet and the length of that cable is about 1200 feet Draw the cable on a coordinate plane letting the x-axis represent the bridge deck and the y-axis represent the tower (Only use positive values of x and y) Write a linear function whose graph models the cable Identify the domain and range writing each as an inequality using set notation and using interval notation

a Domain minusinfin lt x lt +infin x⎪ minusinfin lt x lt +infin (minusinfin +infin)

Range minusinfin lt y lt +infin y⎪ minusinfin lt y lt +infin (minusinfin +infin) End behavior As x rarr +infin f(x) rarr +infin As x rarr -infin f(x) rarr -infin

b Restricted range -64 le y le 64 y⎪ minus64 le y le +64 [-64 64]

c

Since the cable the bridge deck and the

tower form a right triangle find the length

of the leg that lies on the x-axis by using the

Pythagorean Theorem

a 2 + b 2 = c 2

500 2 + b 2 = 1200 2

b asymp 109 1

slope m = 500 - 0 _ 0 - 1091

= 500 _ -1091 asymp -046

The y-intercept is 500

So the linear function is y = -046x + 500

Domain 0 le x le 1091 x⎪0 le x le 1091 [0 1091]

Range 0 le y le 500 y⎪0 le y le 500 [0 500]

Module 1 15 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-B

A2_MTXESE353930_U1M01L1indd 15 11415 241 AM

PEERTOPEER DISCUSSIONIs it possible that a linear function with the domain all real numbers could have a range that is not all real numbers Explain Yes the function could be a

constant function such as f (x) = 2 The domain is

all real numbers but the range is 2

You may want to have students work on the modeling questions in pairs thus providing them with an opportunity to discuss each situation with a partner and decide how to best model the situation using a function

JOURNALHave students describe how to identify the domain and range of a function given its graph or given the situation it models

15 Lesson 1 1

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

0

100

200

300

400450500550

50

150

250

350

Gas used (gal)

Dis

tanc

e tr

avel

ed (m

i)

d

g

161284

20122007

copy H

oug

hton Mifflin H

arcourt Publishin

g Com

pany

The fuel efficiency for a 2007 passenger car was 312 migal For the same model of car the fuel efficiency increased to 356 migal in 2012 The gas tank for this car holds 16 gallons of gas

a Write and graph a linear function that models the distance that each car can travel for a given amount of gas (up to one tankful)

b Write the domain and range of each function using interval notation

c Write and simplify a function ƒ (g) that represents the difference in the distance that the 2012 car can travel and the distance that the 2007 car can travel on the same amount of gas Interpret this function using the graphs of the functions from part a Also find and interpret ƒ (16)

d Write the domain and range of the difference function using set notation

Lesson Performance Task

a For both cars let g be the amount of gas (in gallons) that each car uses and let d be the distance (in miles) that each car travels For the 2007 car the linear model is d 2007 (g) = 312g For the 2012 car the linear model is d 2012 (g) = 356g

b The domain for the 2007 model is [0 16] and the range is [0 4992] The domain for the 2012 model is [0 16] and the range is [0 5696]

c The difference function is f(g) = d 2012 (g) minus d 2007 (g) = 356g minus 312g = 44g This function gives the vertical distance between the graphs of d 2012 (g) and d 2007 (g) For instance when g = 16 the vertical distance between the graphs is f(16) = 44 16 = 704 which means the 2012 car can travel 704 miles farther on a tankful of gas than the 2007 car

d The domain is g⎪0 le g le 16 and the range is f(g)⎪0 le f(g) le 704

Module 1 16 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-A

A2_MTXESE353930_U1M01L1indd 16 22214 319 AM

EXTENSION ACTIVITY

Have students research the average fuel costs per gallon in 2007 and in 2012 Have students use the data to create a new graph representing the distance each car could travel for a given amount of money (up to the cost of a typical full tank) Ask students to describe the aspects of their graphs

QUESTIONING STRATEGIESWhy must restrictions be placed on the domain The tank only holds at most 16

gallons of gas and at least 0 gallons of gas A graph

with a negative number of gallons of gas or more

than 16 gallons of gas would not make sense for

this situation

Why does the domain contain all of the points in the interval and not just the integer

values The amount of gas used is continuous

There is a distance traveled for any value of g in

the domain

INTEGRATE MATHEMATICAL PROCESSESFocus on CommunicationEncourage students to relate the ranges that they wrote for the difference functions to their graphs Have them determine whether the values in the range make sense in the real-world situation Then have students explain whether it makes sense that as the number of gallons used increases the difference in miles traveled by the two cars also increases

Scoring Rubric2 points Student correctly solves the problem and explains hisher reasoning1 point Student shows good understanding of the problem but does not fully solve or explain hisher reasoning0 points Student does not demonstrate understanding of the problem

Domain Range and End Behavior 16

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B

Page 12: CorrectionKey=TX-A CorrectionKey=TX-B LESSON 1 . 1 …€¦ ·  · 2017-01-05A2.7.1 Write the domain and range of a function in interval notation, inequalities, and set notation

0

100

200

300

400450500550

50

150

250

350

Gas used (gal)

Dis

tanc

e tr

avel

ed (m

i)

d

g

161284

20122007

copy H

oug

hton Mifflin H

arcourt Publishin

g Com

pany

The fuel efficiency for a 2007 passenger car was 312 migal For the same model of car the fuel efficiency increased to 356 migal in 2012 The gas tank for this car holds 16 gallons of gas

a Write and graph a linear function that models the distance that each car can travel for a given amount of gas (up to one tankful)

b Write the domain and range of each function using interval notation

c Write and simplify a function ƒ (g) that represents the difference in the distance that the 2012 car can travel and the distance that the 2007 car can travel on the same amount of gas Interpret this function using the graphs of the functions from part a Also find and interpret ƒ (16)

d Write the domain and range of the difference function using set notation

Lesson Performance Task

a For both cars let g be the amount of gas (in gallons) that each car uses and let d be the distance (in miles) that each car travels For the 2007 car the linear model is d 2007 (g) = 312g For the 2012 car the linear model is d 2012 (g) = 356g

b The domain for the 2007 model is [0 16] and the range is [0 4992] The domain for the 2012 model is [0 16] and the range is [0 5696]

c The difference function is f(g) = d 2012 (g) minus d 2007 (g) = 356g minus 312g = 44g This function gives the vertical distance between the graphs of d 2012 (g) and d 2007 (g) For instance when g = 16 the vertical distance between the graphs is f(16) = 44 16 = 704 which means the 2012 car can travel 704 miles farther on a tankful of gas than the 2007 car

d The domain is g⎪0 le g le 16 and the range is f(g)⎪0 le f(g) le 704

Module 1 16 Lesson 1

DO NOT EDIT--Changes must be made through File info CorrectionKey=TX-A

A2_MTXESE353930_U1M01L1indd 16 22214 319 AM

EXTENSION ACTIVITY

Have students research the average fuel costs per gallon in 2007 and in 2012 Have students use the data to create a new graph representing the distance each car could travel for a given amount of money (up to the cost of a typical full tank) Ask students to describe the aspects of their graphs

QUESTIONING STRATEGIESWhy must restrictions be placed on the domain The tank only holds at most 16

gallons of gas and at least 0 gallons of gas A graph

with a negative number of gallons of gas or more

than 16 gallons of gas would not make sense for

this situation

Why does the domain contain all of the points in the interval and not just the integer

values The amount of gas used is continuous

There is a distance traveled for any value of g in

the domain

INTEGRATE MATHEMATICAL PROCESSESFocus on CommunicationEncourage students to relate the ranges that they wrote for the difference functions to their graphs Have them determine whether the values in the range make sense in the real-world situation Then have students explain whether it makes sense that as the number of gallons used increases the difference in miles traveled by the two cars also increases

Scoring Rubric2 points Student correctly solves the problem and explains hisher reasoning1 point Student shows good understanding of the problem but does not fully solve or explain hisher reasoning0 points Student does not demonstrate understanding of the problem

Domain Range and End Behavior 16

DO NOT EDIT--Changes must be made through File infoCorrectionKey=TX-B