Back to Intermediate Algebra 2e

10.1 Finding Composite and Inverse Functions

Chaining one function into another, testing whether a function is one-to-one, and reversing it by swapping the roles of x and y.

Intermediate Algebra 2e, 10.1 Finding Composite and Inverse Functions

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48 exercises

10.1 Exercise 1

Before you get started, take this readiness quiz.

If f(x)=2x−3f \left(x\right) = 2 x - 3 and g(x)=x2+2x−3,g \left(x\right) = x^{2} + 2 x - 3 , find f(4).f \left(4\right) .
If you missed this problem, review the reference.

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10.1 Exercise 2

Solve for x,x , 3x+2y=12.3 x + 2 y = 12 .
If you missed this problem, review the reference.

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10.1 Exercise 3

Simplify: 5(x+4)5−4.5 \frac{\left(x + 4\right)}{5} - 4 .
If you missed this problem, review the reference.

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10.1 Exercise 5

For functions f(x)=3x−2f \left(x\right) = 3 x - 2 and g(x)=5x+1,g \left(x\right) = 5 x + 1 , find ⓐ (f∘g)(x)\left(f \circ g\right) \left(x\right) ⓑ (g∘f)(x)\left(g \circ f\right) \left(x\right) ⓒ (f·g)(x)\left(f \cdot g\right) \left(x\right).

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10.1 Exercise 6

For functions f(x)=4x−3,f \left(x\right) = 4 x - 3 , and g(x)=6x−5,g \left(x\right) = 6 x - 5 , find ⓐ (f∘g)(x),\left(f \circ g\right) \left(x\right) , ⓑ (g∘f)(x),\left(g \circ f\right) \left(x\right) , and ⓒ (f·g)(x).\left(f \cdot g\right) \left(x\right) .

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10.1 Exercise 8

For functions f(x)=x2−9,f \left(x\right) = x^{2} - 9 , and g(x)=2x+5,g \left(x\right) = 2 x + 5 , find ⓐ (f∘g)(−2),\left(f \circ g\right) \left(−2\right) , ⓑ (g∘f)(−3),\left(g \circ f\right) \left(−3\right) , and ⓒ (f∘f)(4).\left(f \circ f\right) \left(4\right) .

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10.1 Exercise 9

For functions f(x)=x2+1,f \left(x\right) = x^{2} + 1 , and g(x)=3x−5,g \left(x\right) = 3 x - 5 , find ⓐ (f∘g)(−1),\left(f \circ g\right) \left(−1\right) , ⓑ (g∘f)(2),\left(g \circ f\right) \left(2\right) , and ⓒ (f∘f)(−1).\left(f \circ f\right) \left(−1\right) .

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10.1 Exercise 10

For each set of ordered pairs, determine if it represents a function and, if so, if the function is one-to-one.

ⓐ {(−3,27),(−2,8),(−1,1),(0,0),(1,1),(2,8),(3,27)}\left\{\left(−3 , 27\right) , \left(−2 , 8\right) , \left(−1 , 1\right) , \left(0 , 0\right) , \left(1 , 1\right) , \left(2 , 8\right) , \left(3 , 27\right)\right\} and ⓑ {(0,0),(1,1),(4,2),(9,3),(16,4)}.\left\{\left(0 , 0\right) , \left(1 , 1\right) , \left(4 , 2\right) , \left(9 , 3\right) , \left(16 , 4\right)\right\} .

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10.1 Exercise 11

For each set of ordered pairs, determine if it represents a function and if so, is the function one-to-one.

ⓐ {(−3,−6),(−2,−4),(−1,−2),(0,0),(1,2),(2,4),(3,6)}\left\{\left(−3 , −6\right) , \left(−2 , −4\right) , \left(−1 , −2\right) , \left(0 , 0\right) , \left(1 , 2\right) , \left(2 , 4\right) , \left(3 , 6\right)\right\} ⓑ {(−4,8),(−2,4),(−1,2),(0,0),(1,2),(2,4),(4,8)}\left\{\left(−4 , 8\right) , \left(−2 , 4\right) , \left(−1 , 2\right) , \left(0 , 0\right) , \left(1 , 2\right) , \left(2 , 4\right) , \left(4 , 8\right)\right\}

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10.1 Exercise 12

For each set of ordered pairs, determine if it represents a function and if so, is the function one-to-one.

ⓐ {(27,−3),(8,−2),(1,−1),(0,0),(1,1),(8,2),(27,3)}\left\{\left(27 , −3\right) , \left(8 , −2\right) , \left(1 , −1\right) , \left(0 , 0\right) , \left(1 , 1\right) , \left(8 , 2\right) , \left(27 , 3\right)\right\} ⓑ {(7,−3),(−5,−4),(8,0),(0,0),(−6,4),(−2,2),(−1,3)}\left\{\left(7 , −3\right) , \left(−5 , −4\right) , \left(8 , 0\right) , \left(0 , 0\right) , \left(−6 , 4\right) , \left(−2 , 2\right) , \left(−1 , 3\right)\right\}

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10.1 Exercise 16

Find the inverse of the function {(0,3),(1,5),(2,7),(3,9)}.\left\{\left(0 , 3\right) , \left(1 , 5\right) , \left(2 , 7\right) , \left(3 , 9\right)\right\} . Determine the domain and range of the inverse function.

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10.1 Exercise 17

Find the inverse of {(0,4),(1,7),(2,10),(3,13)}.\left\{\left(0 , 4\right) , \left(1 , 7\right) , \left(2 , 10\right) , \left(3 , 13\right)\right\} . Determine the domain and range of the inverse function.

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10.1 Exercise 18

Find the inverse of {(−1,4),(−2,1),(−3,0),(−4,2)}.\left\{\left(−1 , 4\right) , \left(−2 , 1\right) , \left(−3 , 0\right) , \left(−4 , 2\right)\right\} . Determine the domain and range of the inverse function.

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10.1 Exercise 23

Verify that the functions are inverse functions.

f(x)=4x−3f \left(x\right) = 4 x - 3 and g(x)=x+34.g \left(x\right) = \frac{x + 3}{4} .

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10.1 Exercise 24

Verify that the functions are inverse functions.

f(x)=2x+6f \left(x\right) = 2 x + 6 and g(x)=x−62.g \left(x\right) = \frac{x - 6}{2} .

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10.1 Exercise 26

Find the inverse of the function f(x)=5x−3.f \left(x\right) = 5 x - 3 .

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10.1 Exercise 27

Find the inverse of the function f(x)=8x+5.f \left(x\right) = 8 x + 5 .

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10.1 Exercise 28

Find the inverse of f(x)=2x−35.f \left(x\right) = \sqrt[5]{2 x - 3} .

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10.1 Exercise 29

Find the inverse of the function f(x)=3x−25.f \left(x\right) = \sqrt[5]{3 x - 2} .

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10.1 Exercise 30

Find the inverse of the function f(x)=6x−74.f \left(x\right) = \sqrt[4]{6 x - 7} .

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10.1 Exercise 31

Find ⓐ (f ∘ g)(x), ⓑ (g ∘ f)(x), and ⓒ (f · g)(x).

f(x)=4x+3f \left(x\right) = 4 x + 3 and g(x)=2x+5g \left(x\right) = 2 x + 5

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10.1 Exercise 33

Find ⓐ (f ∘ g)(x), ⓑ (g ∘ f)(x), and ⓒ (f · g)(x).

f(x)=6x−5f \left(x\right) = 6 x - 5 and g(x)=4x+1g \left(x\right) = 4 x + 1

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10.1 Exercise 35

Find ⓐ (f ∘ g)(x), ⓑ (g ∘ f)(x), and ⓒ (f · g)(x).

f(x)=3xf \left(x\right) = 3 x and g(x)=2x2−3xg \left(x\right) = 2 x^{2} - 3 x

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10.1 Exercise 37

Find ⓐ (f ∘ g)(x), ⓑ (g ∘ f)(x), and ⓒ (f · g)(x).

f(x)=2x−1f \left(x\right) = 2 x - 1 and g(x)=x2+2g \left(x\right) = x^{2} + 2

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10.1 Exercise 39

Find the values described.

For functions f(x)=2x2+3f \left(x\right) = 2 x^{2} + 3 and g(x)=5x−1,g \left(x\right) = 5 x - 1 , find ⓐ (f∘g)(−2)\left(f \circ g\right) \left(−2\right) ⓑ (g∘f)(−3)\left(g \circ f\right) \left(−3\right) ⓒ (f∘f)(−1)\left(f \circ f\right) \left(−1\right)

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10.1 Exercise 41

Find the values described.

For functions f(x)=2x3f \left(x\right) = 2 x^{3} and g(x)=3x2+2,g \left(x\right) = 3 x^{2} + 2 , find ⓐ (f∘g)(−1)\left(f \circ g\right) \left(−1\right) ⓑ (g∘f)(1)\left(g \circ f\right) \left(1\right) ⓒ (g∘g)(1)\left(g \circ g\right) \left(1\right)

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10.1 Exercise 43

Determine if the set of ordered pairs represents a function and if so, is the function one-to-one.

{(−3,9),(−2,4),(−1,1),(0,0)\left\{\right. \left(−3 , 9\right) , \left(−2 , 4\right) , \left(−1 , 1\right) , \left(0 , 0\right),
(1,1),(2,4),(3,9)}\left(1 , 1\right) , \left(2 , 4\right) , \left(3 , 9\right) \left.\right\}

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10.1 Exercise 45

Determine if the set of ordered pairs represents a function and if so, is the function one-to-one.

{(−3,−5),(−2,−3),(−1,−1)\left\{\right. \left(−3 , −5\right) , \left(−2 , −3\right) , \left(−1 , −1\right),
(0,1),(1,3),(2,5),(3,7)}\left(0 , 1\right) , \left(1 , 3\right) , \left(2 , 5\right) , \left(3 , 7\right) \left.\right\}

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10.1 Exercise 51

Find the inverse of each function. Determine the domain and range of the inverse function.

{(2,1),(4,2),(6,3),(8,4)}\left\{\left(2 , 1\right) , \left(4 , 2\right) , \left(6 , 3\right) , \left(8 , 4\right)\right\}

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10.1 Exercise 53

Find the inverse of each function. Determine the domain and range of the inverse function.

{(0,−2),(1,3),(2,7),(3,12)}\left\{\left(0 , −2\right) , \left(1 , 3\right) , \left(2 , 7\right) , \left(3 , 12\right)\right\}

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10.1 Exercise 55

Find the inverse of each function. Determine the domain and range of the inverse function.

{(−2,−3),(−1,−1),(0,1),(1,3)}\left\{\left(−2 , −3\right) , \left(−1 , −1\right) , \left(0 , 1\right) , \left(1 , 3\right)\right\}

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10.1 Exercise 61

Determine whether or not the given functions are inverses.

f(x)=x+8f \left(x\right) = x + 8 and g(x)=x−8g \left(x\right) = x - 8

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10.1 Exercise 63

Determine whether or not the given functions are inverses.

f(x)=7xf \left(x\right) = 7 x and g(x)=x7g \left(x\right) = \frac{x}{7}

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10.1 Exercise 65

Determine whether or not the given functions are inverses.

f(x)=7x+3f \left(x\right) = 7 x + 3 and g(x)=x−37g \left(x\right) = \frac{x - 3}{7}

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10.1 Exercise 67

Determine whether or not the given functions are inverses.

f(x)=x+2f \left(x\right) = \sqrt{x + 2} and g(x)=x2−2(x>0)g \left(x\right) = x^{2} - 2 \left(x > 0\right)

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10.1 Exercise 69

Find the inverse of each function.

f(x)=x−12f \left(x\right) = x - 12

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10.1 Exercise 71

Find the inverse of each function.

f(x)=9xf \left(x\right) = 9 x

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10.1 Exercise 73

Find the inverse of each function.

f(x)=x6f \left(x\right) = \frac{x}{6}

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10.1 Exercise 75

Find the inverse of each function.

f(x)=6x−7f \left(x\right) = 6 x - 7

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10.1 Exercise 77

Find the inverse of each function.

f(x)=−2x+5f \left(x\right) = −2 x + 5

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10.1 Exercise 79

Find the inverse of each function.

f(x)=x2+6,f \left(x\right) = x^{2} + 6 , x≥0x \geq 0

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10.1 Exercise 81

Find the inverse of each function.

f(x)=x3−4f \left(x\right) = x^{3} - 4

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10.1 Exercise 83

Find the inverse of each function.

f(x)=1x+2f \left(x\right) = \frac{1}{x + 2}

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10.1 Exercise 85

Find the inverse of each function.

f(x)=x−2,f \left(x\right) = \sqrt{x - 2} , x≥2x \geq 2

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10.1 Exercise 87

Find the inverse of each function.

f(x)=x−33f \left(x\right) = \sqrt[3]{x - 3}

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10.1 Exercise 89

Find the inverse of each function.

f(x)=9x−54,f \left(x\right) = \sqrt[4]{9 x - 5} , x≥59x \geq \frac{5}{9}

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10.1 Exercise 91

Find the inverse of each function.

f(x)=−3x+55f \left(x\right) = \sqrt[5]{−3 x + 5}

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10.1 Exercise 93

Explain how the graph of the inverse of a function is related to the graph of the function.

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Adapted from Intermediate Algebra 2e © 2020 Rice University. Licensed under CC BY 4.0. Source: Intermediate Algebra 2e. Imported at revision 77a933c.