Precalculus (10th Edition)

Published by Pearson
ISBN 10: 0-32197-907-9
ISBN 13: 978-0-32197-907-0

Chapter 10 - Analytic Geometry - 10.2 The Parabola - 10.2 Assess Your Understanding - Page 647: 28

Answer

$y^2=2x$ Latus rectum points: $(0.5,-1),(0.5,1)$ See graph

Work Step by Step

We are given the parabola: Vertex: $(0,0)$ Directrix: $x=-0.5$ Because the directrix is in the form $x=a$, the parabola is horizontal. Its standard equation is: $(y-k)^2=4p(x-h)$ Use the coordinates of the vertex to determine $h,k$: $(h,k)=(0,0)$ $h=0$ $k=0$ Use the equation of the directrix to determine $p$: $x=h-p=-0.5$ $0-p=-0.5$ $p=0.5$ Determine the parabola's equation: $(y-0)^2=4(0.5)(x-0)$ $y^2=2x$ The focus is: $(h+p,k)=(0+0.5.0)=(0.5,0)$ Determine the two points defining the latus rectum: $x=0.5$ $y^2=2(0.5)$ $y^2=1$ $y=\pm 1$ $y=-1\Rightarrow y_1=-1$ $y=1\Rightarrow y_2=1$ $\Rightarrow (0.5,-1),(0.5,1)$ Plot the points and graph the parabola:
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.