Precalculus: Concepts Through Functions, A Unit Circle Approach to Trigonometry (3rd Edition)

Published by Pearson
ISBN 10: 0-32193-104-1
ISBN 13: 978-0-32193-104-7

Chapter 1 - Functions and Their Graphs - Section 1.7 Building Mathematical Models Using Variation - 1.7 Assess Your Understanding - Page 109: 3


$y=\frac{1}{5} x$

Work Step by Step

$y$ varies directly with $x$, then $y=kx$ where $k$ is the constant of proportionality. Since $y=2$ when $x=10$, then substituting these into the equation above gives: $$2=k (10)\\ \frac{2}{10}=k\\ k=\frac{1}{5}$$ Therefore, the equation is y$=\frac{1}{5}x$ is the required general formula.
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.