9-4 Practice B Operations with Functions

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Holt Algebra 2. All rights reserved. Name. Date. Class. LESSON. 9-4. Practice B. Operations with Functions. Use the following functions for Exercises 1–18. f x. 1.
Name

Date

Class

Practice B

LESSON

9-4

Operations with Functions

Use the following functions for Exercises 1–18. 1 g x   x 2 h x   x  8 f  x   ___ 2x

k x  



x

Find each function. 1.  gk   x 

2.  g ⫹ h   x 

x 2 x

3.  g ⫺ h   x 

x x8 2

x x8 2

4.  fg   x 

 

f   6. __ g x

5.  gh   x 

x __

x  8x 3

2

1 ____

2

2x 3

Find each value. 7. g  k  9  

8. h  g  ⫺3  

9. g  h  ⫺3  

9

1

10. k  h  12  

121

11. f  g  4  

12. f  h  1  

1 ___

2

1 ___ 14

32

Write each composite function. State the domain of each. 13. f  g  x  

1 ; f  g  x    ____ 2x 2 {x | x  0}

16. f  k  x  

f k x   

 x ___

2x {x | x  0}

;

14. h  g  x   h g x  

15. h  k  x  

 x  8; {x | x is a real number} 2

17. k  g  x  

h  k  x     x  8; {x | x  0} 18. k  h  x  

k  g  x    x ; {x | x is a real number}



k  h  x    x  8 ; {x | x  8}

Solve. 19. A retail shoe store manager sets the price of shoes at twice his cost. The shoe store is now offering a 40% discount on all shoes. a. Write a composite function for the price of a pair of shoes after the discount.

f  g  x    1.2x

b. If a pair of shoes cost the manager $25, what is the sale price?

$30

Copyright © by Holt, Rinehart and Winston. All rights reserved.

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5/16/06 4:03:24 PM