Algebra 2 Unit 8a
Name:
Rational Functions
Assignment #39 Inverse Variation
Find the Missing Variable:
1) y varies directly with x. If y = -4 when x = 2, find y when x
= -6.
2) y varies inversely with x. If y = 40 when x = 16, find x when
y = -5.
3) y varies inversely with x. If y = 7 when x = -4, find y when
x = 5.
4) y varies directly with x. If y = 15 when x = -18, find y when
x = 1.6.
5) y varies directly with x. If y = 75 when x =25, find x when y
= 25.
Classify the following as: a) Directb) Inverse c) Neither
6) m = -5p9) c = 12) c = 3v
7) r = 10) n = f13) u =
8) d = 4t11) z =
What is the constant of variation for the following?
14) d = 4t 15) z = 16) n = f 17) r =
Answer the following questions.
18) If x and y vary directly, as x decreases, what happens to
the value of y?
19) If x and y vary inversely, as y increases, what happens to
the value of x?
20) If x and y vary directly, as y increases, what happens to
the value of x?
21) If x and y vary inversely, as x decreases, what happens to
the value of y?
Classify the following graphs as a) Direct b) Inverse c)
Neither
22) 23)
24)25)
Algebra 2 Unit 8a
Name:
Rational Functions
Assignment #40 Inverse Variation
Write the function that models each variation. Find when and
.
1. varies directly with and inversely with . When and ,
2. varies jointly with and . When and ,
3. varies inversely with the product of and . When and ,
Answer the following questions:
4. The electric current I, is amperes, in a circuit varies
directly as the voltage V. When 12 volts are applied, the current
is 4 amperes. What is the current when 18 volts are applied?
5. The volume V of gas varies inversely to the pressure P. The
volume of a gas is 200 cm3 under pressure of 32 kg/cm2. What will
be its volume under pressure of 40 kg/cm2?
6. The number of kilograms of water in a persons body varies
directly as the persons mass. A person with a mass of 90 kg
contains 60 kg of water. How many kilograms of water are in a
person with a mass of 50 kg?
7. On a map, distance in km and distance in cm varies directly,
and 25 km are represented by 2cm. If two cities are 7cm apart on
the map, what is the actual distance between them?
8. The time it takes to fly from Los Angeles to New York varies
inversely as the speed of the plane. If the trip takes 6 hours at
900 km/h, how long would it take at 800 km/h?
Is the relationship between the values in each table a direct
variation, an inverse variation, or neither? Write equations to
model the direct and inverse variations.
9.
3
15
8
40
10
50
22
110
10.
3
14
5
8.4
7
6
10.5
4
11.
0.5
1
2.1
4.2
3.5
7
11
22
12. A persons body mass index (BMI) varies directly with his or
her weight in pounds and inversely with the square of his or her
height in inches. A student with a height of 68 in. and a weight of
150 lb. has a BMI of 22.8. What is the BMI of a student with a
height of 61 in. and a weight of 115 lb?
18
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2
.
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2
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9
4
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