Direct and Inverse Variation

Direct Variation

100

Which one is an example of direct Variation: y = 5x OR -3x + 2y =0 First, Second, Both, or Neither

Both

200

Is y/x = 8 an example of direct variation?

yes

300

true of false. 7y=x is an example of direct variation

false

400

Does the data in this table represent that y varies directly with x? if it does write an equation. x: 4, 5, 11 y: 3, 4.5, 13.5

Is not Direct Variation.

500

write a direct variation equation for the data

x: -4, -3, -1

y: 20, 15, 5

y = -5x

Inverse Variation

100

If y varies inversely with x, write and equation. x=9 and y=4

y=36/x

200

The cost of a $100 wedding gift is being split between multiple people. Create a table when x: 3, 4, 5

y: 33.33, 25, 20

300

Is xy = 13 a inverse equation?

yes

400

Does the table show inverse variation?

x: 2,4,6

y: 24,16,12?

no

500

the x values for the equation y = 3/x are shown below. Find the y values

x: 1, 3, .5

y: 3,1,6

Solve for the Constant

100

Find the Constant: x: 2, 7, 10 y: 35, 10, 7

K=70

200

Find the Constant: x: 1.2, 1.5, 2.4 y: 5, 4, 2.5

K=6

300

Find the Constant: x: 2, 6, 10 y: 4.2, 12.6, 21

k=2.1

400

Find the Constant: x: 2, 8, 16 y: 9, 36, 72

k=4.5

500

Find the Constant: x: 0, 2, 4, 6 y: 3, 5, 7, 9

There is no constant, this is not direct or inverse variation.

Write an Equation

100

x and y vary inversely. when x=4, y=-3

y=-12/x

200

x and y vary inversely. when x=.5, y=16

y=8/x

300

x and y vary inversely. when x=6, y=2/3

y=4/x

400

x and y vary inversely. when x=1/4, y=-24

y = -6/x

500

x and y vary inversely. when x = 4/2, y = 1/2

y = 1/x

Create a Table

100

F(x)= 2x When x: 1, 2, 3

y: 2, 4, 6

200

f(x)= 3x - 2 When x: 1, 2, 3

y: 1, 4, 7

300

f(x)= -.5x When x: -2, -1, 0, 1, 2

y: 1, .5, 0, -.5, -1

400

f(x)= 6/x When x: 1, 2, 3

y: 6, 3, 2 

500

f(x)= 12/x  , x: .5, 2, 4

y: 24, 6, 3