topic badge
AustraliaVIC
VCE 11 General 2023

9.04 Inverse variation

Worksheet
Inverse variation
1

State the meaning of inverse proportion.

2

If r varies inversely with a, write an equation that uses k as the constant of variation.

3

In the equation y = \dfrac{18}{x}, y varies inversely with x. When x = 6, y = 3.

a

Solve for y when x = 2.

b

For these two ordered pairs, what is the result when the y -value is multiplied by the x -value?

4

Suppose that y varies inversely as the square of x, and that y = 0.0023 when x = 0.4.

a

Find the constant of variation, k. Round your answer correct to six decimal places.

b

Write the variation equation for y in terms of x.

5

State whether the following equations are examples of inverse variation:

a

y = \dfrac{7}{x}

b

y = 6 x + 8

c

y = - \dfrac{9}{x}

d

y = \dfrac{8}{x^{2}}

e

y = 2 x^{2} - 7 x - 4

f

y = 3 - x

g

x = 1 + y^{3}

h

x = \dfrac{8}{y^{2}}

i

y = 6 x + 8

j

x y = - 7

k

x = \dfrac{2}{y}

l

x y = 5 x

6

Consider the inverse variation equation y = \dfrac{6}{x}.

a

Complete the following tables:

x\dfrac{1}{4}\dfrac{1}{2}124
y
b

Plot the data from the table of values on a number plane.

7

If y is inversely proportional to x, and y = 20 when x = 10:

a

Find the constant of variation, k.

b

Express y in terms of x.

c

Find the value of y when x = 5.

8

Which of the following tables could represent an inversely proportional relationship between x and y?

A
x1234
y31.510.75
B
x1234
y3618129
C
x15610
y375108300
D
x1234
y4567
9

Find the equation relating n and r given the table of values:

n1234
r5\dfrac{5}{2}\dfrac{5}{3}\dfrac{5}{4}
10

Consider the equation s = \dfrac{375}{t}.

a

State the constant of proportionality.

b

Find the value of s when t = 6.

c

Find the value of s when t = 12.

11

The time, t, taken by a typist to type up a document is inversely proportional to his typing speed, s. That is, the quicker the typing speed, the less time it will take. If it takes a typist 20 minutes to type a particular document, typing at a speed of 61 words per minute:

a

Find the constant of variation k.

b

How long (in minutes) will it take a typist with a typing speed of 30.5 words per minute to type up the document?

Sign up to access Worksheet
Get full access to our content with a Mathspace account

Outcomes

U2.AoS3.1

the concepts of direct and inverse variation

U2.AoS3.4

solve problems which involve the use of direct or inverse variation

What is Mathspace

About Mathspace