Precalculus (10th Edition)

Published by Pearson
ISBN 10: 0-32197-907-9
ISBN 13: 978-0-32197-907-0

Chapter 2 - Functions and Their Graphs - 2.3 Properties of Functions - 2.3 Assess Your Understanding - Page 80: 74

Answer

(a) $-5$ (b) $y=-5x$

Work Step by Step

(a) Given $h(x)=-2x^2+x$, the average rate of change $R$ is given by the formula $$R=\frac{h(x_2)-h(x_1)}{x_2-x_1}$$ From $x_1=0$ to $x_2=3$, we have: $$R=\frac{h(3)-h(0)}{3-0}=\frac{-2(3)^2+(3)-(-2(0)^2+(0))}{3}=-5$$ (b) The slope of the secant line is the average rate of change $m=-5$. To find the equation of the line, we need to use the coordinates of one point on the line. Since the line contains $(0,h(0))$, find $h(0)$. $h(0)=-2(0^2)+0=0$ Thus, the line contains the point $(0, 0)$. Therefore, using the point-slope form, the equation of the line is: $$\begin{align*} y-0&=-5(x-0)\\ y&=-5x \end{align*}$$
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.