Thomas' Calculus 13th Edition

Published by Pearson
ISBN 10: 0-32187-896-5
ISBN 13: 978-0-32187-896-0

Chapter 5: Integrals - Section 5.6 - Definite Integral Substitutions and the Area Between Curves - Exercises 5.6 - Page 303: 31

Answer

$\displaystyle \frac{128}{15}$

Work Step by Step

On the interval $[-2,2]$, the graph of $y=2x^{2}$ is above the graph of $y=x^{4}-2x^{2}$, The area between the two graphs over [a,b], where one graph is above the other, is given with $\displaystyle \int_{a}^{b}(y_{above}-y_{below})dt$. Thus, $A=\displaystyle \int_{-2}^{2}[2x^{2}-(x^{4}-2x^{2})]dx=\int_{-2}^{2}(4x^{2}-x^{4})dx$ $=4\displaystyle \int_{-2}^{2}x^{2}dx -\int_{-2}^{2}x^{4}dx$ $=4[\displaystyle \frac{x^{3}}{3}]_{-2}^{2}-[\frac{x^{5}}{5}]_{-2}^{2}$ $=4(\displaystyle \frac{2^{3}}{3}-\frac{(-2)^{3}}{3})-[\frac{32}{5}-(-\frac{32}{5})]$ $=\displaystyle \frac{64}{3}-\frac{64}{5}$ $=\displaystyle \frac{64(5)-64(3)}{15}$ = $\displaystyle \frac{128}{15}$
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.