Precalculus: Mathematics for Calculus, 7th Edition

Published by Brooks Cole
ISBN 10: 1305071751
ISBN 13: 978-1-30507-175-9

Chapter 1 - Section 1.9 - The Coordinate Plane; Graphs of Equations; Circles - 1.9 Exercises - Page 103: 73

Answer

$a)$ $x$-intercepts: $\pm2;$ $y$-intercept: None $b)$ $x$-intercept: $\dfrac{1}{4};$ $y$-intercept: $1$

Work Step by Step

$a)$ $9x^{2}-4y^{2}=36$ To find the $x$-intercepts, set $y$ equal to $0$ and solve for $x$: $9x^{2}-4y^{2}=36$ $9x^{2}-4(0)^{2}=36$ $9x^{2}=36$ $x^{2}=\dfrac{36}{9}$ $x^{2}=4$ $x=\pm\sqrt{4}$ $x=\pm2$ To find the $y$-intercept, set $x$ equal to $0$ and solve for $y$: $9x^{2}-4y^{2}=36$ $9(0)^{2}-4y^{2}=36$ $-4y^{2}=36$ $y^{2}=\dfrac{36}{-4}$ $y^{2}=-9$ $y=\pm\sqrt{-9}$ Since solving for $y$ yields a complex solution, this equation does not have $y$-intercept. $b)$ $y-2xy+4x=1$ To find the $x$-intercept, set $y$ equal to $0$ and solve for $x$: $y-2xy+4x=1$ $0-2x(0)+4x=1$ $4x=1$ $x=\dfrac{1}{4}$ To find the $y$-intercept, set $x$ equal to $0$ and solve for $y$: $y-2xy+4x=1$ $y-2(0)y+4(0)=1$ $y=1$
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.