Upload
renee-tan
View
245
Download
0
Tags:
Embed Size (px)
DESCRIPTION
Review of Functions
Citation preview
PSHS 3RD YEAR MATH
Session 1
1. Evaluate the function for f(-1) if
21 1 1 1f
2( ) 1f x x x
Diagnostic - Answers
1 1 11
2. What is the sum h(x) + g(x) if h(x) = 5x – 1 and g(x) = 3x2 + 6x – 7 ?
25 1 3 6 7h x g x x x x 23 11 8x x
3. If F(x)= 2x + 3 and G(x) = 5x – 4, what is the composite function
G(F(x))? 5 4G F x F x
5 2 3 4x 10 15 410 11
xx
4. What is the domain of the square root function ?
• DOMAIN The set of all possible values for x, OR The x-coordinates of the points of the graph
of the function
( )f x x 5
2 ways to analyze:1.) Knowing the graph of the function2.) Using the given equation of the function
The graph of y x
What are the x-coordinates of the points on the graph? 0 to DOMAIN
The graph of ( )f x x 5
• Courtesy of Wolfram Alpha: www/wolframalpha.com• GENERAL EQUATION: y a x h k
at x=5
h=horizontal shift
DOMAIN of
is5x
( )f x x 5
5. Function or not?Relation Function Not a
Functiona.{(5,6), (-2,3), (3,1), (5,2), (8, -
4) } b. y = 9 – x2
c.
d. x = (y + 6) (y – 3)
-1 1
-2
6. Find the inverse of the function . • HOW TO GET• 1.) Use y for “f(x)”.• 2.) Switch x and y.• 3.) Isolate y.• 4.) This new y will be
your
1f x
2 3f x x 1f x
1f x
2 3y x 2 3x y
32
xy
132
xf x
7. Which of the following is NOT divisible by (x – 1) ?
• 3 Ways to answer:1.) Using LONG division.2.) Using SYNTHETIC division.3.) Using the REMAINDER THEOREM.Remainder Theorem:
3 2
3 2
3 4
1 3 1 4 0
x x
Therefore,
is divisible by(x - 1).
3 23 4x x
8. What are the roots of the function ? • ROOTS – also known as the x-coordinates of
the x-intercepts, OR the solutions to the equation if h( x ) were equal 0.
• HOW DO WE GET THE x-intercepts?• Let y = 0, meaning let h( x ) = 0.
3 22 15h x x x x
3 20 2 15x x x
3 2
2
0 2 15
0 2 15
0 5 3
x x x
x x x
x x x
Which is the correct set of roots of f( x )?
x = -3, 0 and 5OR
x = -5, 0 and 3
9. What is the equation of the line that passes through (5, -6) and is perpendicular to the line whose equation is ?• Point (5, -6) is a point on the line we are
looking for.• Perpendicular means that the slopes of
• and the unknown line are NEGATIVE RECIPROCALS of each other.
4 16 0x y
4 16 0x y
10. Given the function :• Find the intercepts.• To get the x-intercept:
• Therefore, • x-intercept = (1/2, 0).
1 2f x x
0 1 22 1
1
2
xx
x
1 2 0
1
y
y
• To get the y-intercept:
Therefore, y-intercept = (0, 1).
10.b. Graph the function.
11. Given the function :
• Find the vertex of the parabola.• 2 ways:• 1.) Vertex-form of the quadratic equation.
• 2.) Use the vertex formula.
24 1 2f x x
2y a x h k
24: ,
2 4b ac b
vertexa a
11.b. Find the domain and range.
• Domain – set of all real numbers: • Range – based on 2 things:• 1.) the y-coordinate of the VERTEX of the
parabola. • 2.) the direction where the parabola is
opening leading coefficient. • Therefore, the range is 2y
x
11.c. Graph the function.
Vertex: (1, 2)
Trigonometric functions
• Sine, Cosine, and Tangent• These are RATIOS of the sides of the right
triangle
sinopposite
hypotenuse
cosadjacent
hypotenuse tan
oppositeadjacent
SOH CAH TOA
RECALL: Pythagorean Theorem
a
b
c
If side a = 5 cm. and side c = 13 cm., what is the length of side b?
2 2 2a b c
where a and b are the LEGS, and c is the hypotenuse.
RECALL: The 30-60-90 TRIANGLE THEOREMS
• The side opposite 30 degrees will have a length of ½ of the length of the longest side (hypotenuse).
• The side opposite 60 degrees will be times the length of the longest side.
30
60
32
a
b
c
RECALL: THE 45-45-90 TRIANGLE
• In terms of the sides, what kind of triangle is the 45-45-90 triangle?
• The length of the longest side is times the length of a leg.
a
c
a
2
Trigonometric identities
sintan
cos
1
cscsin
1sec
cos
1cot
tan
2 2sin cos 1
THE UNIT CIRCLE
For angle measuresgreater than 90 deg,we use REFERENCE ANGLES.
Reference anglesAngle rotation starts from the positive x-axis, then moving counter-clockwise.The reference angle is measured from the x-axis.
What is the reference Angle of the ff?1.) 120 deg =2.) 225 deg =3.) 330 deg =
UNITS OF ANGLES: DEGREES & RADIANS
360 2 180
902
454
603
306
What IF YOU FORGOT THE CONVERSIONS?
• What is 270 degrees in radian measure?
• Just memorize one thing:
360 2702 ?
360 2
What are the trigonometric function values of the ff. angles?
Angle Sin x Cos x Tan x Csc x Sec x Cot x
240 deg
-225 deg
-150 deg
Using the periodicity of the sine and cosine functions
171. sin
4
72. cos
6
5
3. tan3
GRAPHS OF THE TRIGONOMETRIC FUNCTIONS
FEATURES of y = sin x
1. Amplitude2. Period3. Phase shift (horizontal)4. Vertical shift
siny x
siny x2siny x
siny x
sin 3y x
siny x sin2
y x
siny x sin2y x
Transformations of the graphsin( )y a bx c k
a - amplitude
k – Vertical shiftc
c/b – Horizontal (phase) shift
b/ (2pi) - Period