Precalculus: Mathematics for Calculus, 7th Edition

Published by Brooks Cole
ISBN 10: 1305071751
ISBN 13: 978-1-30507-175-9

Chapter 11 - Section 11.4 - Shifted Conics - 11.4 Exercises - Page 815: 44

Answer

$\frac{(x-3)^2}{9}+\frac{y^2}{25}=1$

Work Step by Step

Step 1. As the foci are on the y-axis, assume the ellipse has a general form $\frac{(x-h)^2}{b^2}+\frac{(y-k)^2}{a^2}=1$ Step 2. Based on the foci coordinates, we have $2c=4+4$ and $c=4$ Step 3. Based on the foci positions, we can identify the center as $(3,0)$, thus $h=3,k=0$ Step 4. The x-intercepts gives points on the curve $(0,0)$ and $(6,0)$ Step 5. Plug-in one of the above point to the equation, we have $\frac{(0-3)^2}{b^2}+\frac{(0)^2}{a^2}=1$ which gives $b^2=9$ Step 6. Use the relationship $a^2=b^2+c^2$, we have $a^2=9+16=25$ Step 7. Conclusion: the ellipse equation is $\frac{(x-3)^2}{9}+\frac{(y)^2}{25}=1$
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.