Precalculus (6th Edition) Blitzer

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

Chapter 9 - Review Exercises - Page 1035: 33

Answer

vertex $(2,-2)$, focus $(2,-\frac{3}{2})$, and directrix $y=-\frac{5}{2}$; see figure.

Work Step by Step

Step 1. Rewrite the equation as $x^2-4x+4=2y+4$ or $(x-2)^2=2(y+2)$; we have $p=\frac{2}{4}=\frac{1}{2}$ Step 2. We can identify that this parabola opens upwards with a vertex at $(2,-2)$, focus at $(2,-2+\frac{1}{2})$ or $(2,-\frac{3}{2})$, and directrix as $y=-2-\frac{1}{2}=-\frac{5}{2}$ Step 3. We can graph the equation as shown in the figure.
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.