Precalculus (6th Edition) Blitzer

Published by Pearson
ISBN 10: 0-13446-914-3
ISBN 13: 978-0-13446-914-0

Chapter 9 - Section 9.3 - The Parabola - Exercise Set - Page 997: 21

Answer

$x^2=60y$

Work Step by Step

Standard form of a parabola is given as: $x^2=4py$ ...(1) Formula to find focus is: $F(0,p)$ and formula to find directrix is: $y=-p$ or, $y+p=0$ As we are given that focus is: $(0,15)$ and directrix is: $y=-15$ or $x+15=0$ Plug all these data in equation (1), we have: $p=15$ Thus, $x^2=4(15)y \implies x^2=60y$
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.