Functions Modeling Change: A Preparation for Calculus, 5th Edition

Published by Wiley
ISBN 10: 1118583191
ISBN 13: 978-1-11858-319-7

Chapter 3 - Quadratic Functions - Exercises for Skills for Factoring - Page 135: 100

Answer

$\left(\frac{3-3\sqrt{7}}{2},\frac{-3 -3\sqrt{7}}{2}\right),\left(\frac{3+3\sqrt{7}}{2},\frac{-3+3\sqrt{7}}{2}\right)$

Work Step by Step

Substituting the value of $y$ from the second equation into the first equation, we obtain $$ \begin{aligned} x^2+(x-3)^2 & =36 \\ x^2+x^2-6 x+9 & =36 \\ 2 x^2-6 x-27 & =0 \end{aligned} $$ $$ \begin{aligned} x & =\frac{-(-6) \pm \sqrt{(-6)^2-4(2)(-27)}}{(2)(2)} \\ & =\frac{6 \pm \sqrt{252}}{4} \\ & =\frac{6 \pm \sqrt{4 \cdot 9\cdot 7}}{4} \\ & =\frac{6 \pm 6 \sqrt{7}}{4} \\ & =\frac{3 \pm 3\sqrt{7}}{2} . \end{aligned} $$ Now we substitute the values of $x$ into the second equation: $$ \begin{aligned} x_1&=\frac{3-3\sqrt{7}}{2}\\ y_1 & =\frac{3-3\sqrt{7}}{2}-3 \\ & =\frac{-3 -3\sqrt{7}}{2}\\ x_2&=\frac{3+3\sqrt{7}}{2}\\ y_2 & =\frac{3+3\sqrt{7}}{2}-3 \\ & =\frac{-3 +3\sqrt{7}}{2} \end{aligned} $$ The solutions are: $$\left(\frac{3-3\sqrt{7}}{2},\frac{-3 -3\sqrt{7}}{2}\right),\left(\frac{3+3\sqrt{7}}{2},\frac{-3+3\sqrt{7}}{2}\right)$$
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.