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 996: 4


Focus is: $(-1,0)$ and directrix is: $x=1$; $\bf{Graph (d)}$

Work Step by Step

Standard form of a parabola is given as: $y^2=4px$ ...(1) Formula to find focus is: $F(p,0)$ and formula to find directrix is: $x=-p$ As we are given that $y^2=-4x$ Compare this form with the equation (1), we have: $p=-1$ Thus, Focus is: $(-1,0)$ and directrix is: $x=1$ All the above information matches to the $\bf{Graph (d)}$
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.