College Algebra, 2013a

370 Further Topics in Functions
In Exercises 25 - 30, usef(x) =−2x, g(x) = √ x and h(x) =|x| to find and simplify expressions
for the following functions and state the domain of each using interval notation.
25. (h ◦ g ◦ f)(x) 26. (h ◦ f ◦ g)(x) 27. (g ◦ f ◦ h)(x)
28. (g ◦ h ◦ f)(x) 29. (f ◦ h ◦ g)(x) 30. (f ◦ g ◦ h)(x)
In Exercises 31 - 40, write the given function as a composition of two or more non-identity functions.
(There are several correct answers, so check your answer using function composition.)
31. p(x) =(2x +3) 3 32. P (x) = ( x 2 − x +1 ) 5
33. h(x) = √ 2x − 1 34. H(x) =|7 − 3x|
35. r(x) = 2
5x +1
37. q(x) =
39. v(x) =
|x| +1
|x|−1
2x +1
3 − 4x
41. Write the function F (x) =
36. R(x) = 7
x 2 − 1
38. Q(x) = 2x3 +1
x 3 − 1
40. w(x) = x2
x 4 +1
√
x 3 +6
x 3 as a composition of three or more non-identity functions.
− 9
42. Let g(x) =−x, h(x) =x+2,j(x) =3x and k(x) =x−4. In what order must these functions
be composed with f(x) = √ x to create F (x) =3 √ −x +2− 4?
43. What linear functions could be used to transform f(x) =x 3 into F (x) =− 1 2 (2x − 7)3 +1?
What is the proper order of composition?
In Exercises 44 - 55, letf be the function defined by
and let g be the function defined
. Find the value if it exists.
f = {(−3, 4), (−2, 2), (−1, 0), (0, 1), (1, 3), (2, 4), (3, −1)}
g = {(−3, −2), (−2, 0), (−1, −4), (0, 0), (1, −3), (2, 1), (3, 2)}
44. (f ◦ g)(3) 45. f(g(−1)) 46. (f ◦ f)(0)
47. (f ◦ g)(−3) 48. (g ◦ f)(3) 49. g(f(−3))