Intermediate Algebra (12th Edition)

Published by Pearson
ISBN 10: 0321969359
ISBN 13: 978-0-32196-935-4

Chapter 9 - Section 9.1 - Inverse Functions - 9.1 Exercises - Page 589: 15

Answer

one-to-one function inverse: $f^{-1}(x)=-2x-4$

Work Step by Step

Some of the ordered pairs of the given function, $ f(x)=-\dfrac{1}{2}x-2 $, are $ \left\{(-4,0)(-2,-1),(0,-2),(2,-3),(4,-4),...\right\} $. Note that every $y$-coordinate from this function is unique. Hence, the given function is a one-to-one function. To find the inverse, let $y=f(x)$. Then, interchange the $x$ and $y$ variables and solve for $y$. That is, \begin{align*} y&=-\dfrac{1}{2}x-2 \\&\Rightarrow x=-\dfrac{1}{2}y-2 &(\text{interchange $x$ and $y$}) \\\\& x+2=-\dfrac{1}{2}y &(\text{solve for $y$}) \\\\& (-2)(x+2)=\left(-\dfrac{1}{2}y\right)(-2) \\\\& -2x-4=y \\& y=-2x-4 .\end{align*} Hence, the inverse is $ f^{-1}(x)=-2x-4 $.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.