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 814: 27

Answer

(a) Center: $C(-1,4)$ $V_1(-1,-2)$ and $V_2(1,10)$ $F_1(-1,4-2\sqrt {10})$ and $F_2(-1,4+2\sqrt {10})$ $y=3x+7$ $y=-3x+1$ (b)

Work Step by Step

Equation of a hyperbola with center at $(h,k)$ (transverse axis is vertical): $\frac{(y-k)^2}{a^2}-\frac{(x-h)^2}{b^2}=1$ $36x^2+72x-4y^2+32y+116=0$ $36x^2+72x+36-4y^2+32y-64=-116+36-64$ $36(x+1)^2-4(y-4)^2=-144$ $\frac{(y-4)^2}{36}-\frac{(x+1)^2}{4}=1$ $\frac{(y-4)^2}{6^2}-\frac{[x-(-1)]^2}{2^2}=1$ $h=-1$ $k=4$ Center: $C(-1,4)$ $a=6$ $b=2$ $c^2=a^2+b^2=6^2+2^2=36+4=40$ $c=2\sqrt {10}$ The given equation can be obtained by shifting $\frac{y^2}{6^2}-\frac{x^2}{2^2}=1$ left 1 unit and upward 4 units. In $\frac{y^2}{6^2}-\frac{x^2}{2^2}=1$: Vertices: $V(0,±a)$ $V_1(0,-6)$ and $V_2(0,6)$ Foci: $F(0,±c)$ $F_1(0,-2\sqrt {10})$ and $F_2(0,2\sqrt {10})$ Now, shift these points 1 unit to the left and 8 units upward: $V_1(-1,-2)$ and $V_2(1,10)$ $F_1(-1,4-2\sqrt {10})$ and $F_2(-1,4+2\sqrt {10})$ Asymptotes: $(y−k)=±\frac{a}{b}(x−h)$ $y-4=±\frac{6}{2}[x-(-1)]$ $y-4=±3(x+1)$ $y=3x+7$ and $y=-3x+1$
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.