Precalculus: Mathematics for Calculus, 7th Edition

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

Chapter 11 - Review - Test - Page 835: 6

Answer

$\frac{y^2}{9}-\frac{x^2}{16}=1$

Work Step by Step

The foci lie on the y-axis. Also, the origin is the center because it is the midpoint between the foci: $\frac{(0,5)+(0,-5)}{2}=(0,0)$. So: $\frac{y^2}{a^2}-\frac{x^2}{b^2}=1$ Asymptotes: $y=±\frac{a}{b}x=±\frac{3}{4}x$ $\frac{a}{b}=\frac{3}{4}$ $a=\frac{3}{4}b$ Foci: $F(0,±c)=F(0,±5)$ $c=5$ $c^2=a^2+b^2$ $25=(\frac{3}{4}b)^2+b^2$ $25=\frac{9}{16}b^2+b^2=\frac{25}{16}b^2$ $b^2=16$ $b=4$ $a=\frac{3}{4}b=3$ Finally: $\frac{y^2}{3^2}-\frac{x^2}{4^2}=1$ $\frac{y^2}{9}-\frac{x^2}{16}=1$
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.