Download Section 2-2 and 8-1 Day 2 Practice Worksheet

Name: ______________________________________________________ Date: _______________________ Period: _________
Algebra 2
Section 2-2 & 8-1 Practice
Direct and Inverse Variation
Write the equation for a Direct Variation: ______________________________________________
Write the equation for an Inverse Variation: ____________________________________________
For each function, determine whether y varies directly with x. If so, find the
constant of variation and write the function rule. To start, write ratios of output
to input.
1.
x
y
3
2.
x
y
–9
2
4
–12
5
–15
3.
x
y
6
–4
–8
5
10
1
2
10
30
3
6
Determine whether y varies directly with x. If so, find the constant of the variation.
4. y = 5x
5. 3y = 4x + 6
6. y 
7
x
For Exercises 7–10, y varies directly with x.
7. If y = −2 when x = 1, find x when y = 4.
8. If y = 4 when x = 5, find y when x = 10.
9. If y = 12 when x = 36, find x when y = 7.
10. If y = 121 when x = 11, find y when x = 5.
Is the relationship between the values in each table a direct variation, an inverse variation, or neither?
Write an equation to model the direct and inverse variations.
11.
12.
x
0.1
3
3
0.1
6
0.05
24
13.
y
0.0125
x
y
1
2
5
6
3
6
15
18
x
y
0
2
4
6
1
5
7
8
Suppose that x and y vary inversely. Write a function that models each inverse variation. Graph the
function and find y when x = 10.
14. x = 2 when y = − 4
15. x = − 9 when y = − 1
16. x = 1.5 when y = 10
Each ordered pair is from an inverse variation. Find the constant of variation.
17. (2, 2)
18. (1, 8)
19. (9, 4)