College Algebra (10th Edition)

Published by Pearson
ISBN 10: 0321979478
ISBN 13: 978-0-32197-947-6

Chapter 7 - Section 7.3 - The Ellipse - 7.3 Assess Your Understanding - Page 525: 19

Answer

Center at $(0,0).$ Vertices at $(0,\pm 5).$ Foci at $(0,\pm 4)$

Work Step by Step

$\displaystyle \frac{x^{2}}{3^{2}}+\frac{y^{2}}{5^{2}}=1\qquad $.... Center at $(0,0)$. The greater denominator is $a^{2}=5^{2}$, it is below $y^{2}$ so the major axis is along the y-axis. Apply the theorem: An equation of the ellipse with center at $(0,0),$ foci at $(0,-c)$ and $(0,c),$ and vertices at $(0,-a)$ and $(0,a)$ is $\displaystyle \frac{x^{2}}{b^{2}}+\frac{y^{2}}{a^{2}}=1\quad $ where $a \gt b \gt 0$ and $b^{2}=a^{2}-c^{2}$ $a=5,\quad b=3$ Center at $(0,0).$ Vertices at $(0,\pm 5).$ Find $c$ from $b^{2}=a^{2}-c^{2}$ $c^{2}=a^{2}-b^{2}$ $c^{2}=25-9$ $c^{2}=16$ $c=4$ Foci at $(0,\pm 4)$
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.