Calculus: Early Transcendentals 9th Edition

Published by Cengage Learning
ISBN 10: 1337613924
ISBN 13: 978-1-33761-392-7

Chapter 10 - Section 10.5 - Conic Sections - 10.5 Exercises - Page 709: 26

Answer

Equation: $\frac{y^2}{4}-\frac{x^2}{8}=1$ Foci: $(0,\pm2\sqrt{3})$ Asymptotes: $y=\pm\frac{1}{\sqrt{2}}x$

Work Step by Step

Recall: The hyperbola whose the vertices are $(0,\pm a)$ has the equation $\frac{y^2}{a^2}-\frac{x^2}{b^2}=1$. In the figure, the vertices are $(0,\pm2)$. We get $a=2$ and so $a^2=4$. The hyperbola also passes through the point $(8,6)$. Then, $\frac{y^2}{a^2}-\frac{x^2}{b^2}=1$ $\frac{6^2}{4}-\frac{8^2}{b^2}=1$ $\frac{36}{4}-\frac{64}{b^2}=1$ $9-\frac{64}{b^2}=1$ $\frac{64}{b^2}=8$ $b^2=8$ So, the equation of the hyperbola is $\frac{y^2}{4}-\frac{x^2}{8}=1$. Find the value of $c$: $c=\sqrt{a^2+b^2}=\sqrt{4+8}=\sqrt{12}=2\sqrt{3}$ Find the foci: $(0,\pm c)=(0,\pm2\sqrt{3})$ Find the asymptotes: $y=\pm (a/b)x$ $y=\pm (2/\sqrt{8})x$ $y=\pm 1/\sqrt{2}x$
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.