Calculus (3rd Edition)

Published by W. H. Freeman
ISBN 10: 1464125260
ISBN 13: 978-1-46412-526-3

Chapter 8 - Techniques of Integration - Chapter Review Exercises - Page 460: 13

Answer

$$\frac{5}{32} e^{4}-\frac{1}{32}$$

Work Step by Step

Given $$\int_{0}^{1} x^{2} e^{4 x} d x$$ Let \begin{align*} u&= x^2\ \ \ \ \ \ \ \ \ dv= e^{4x}dx\\ du&= 2xdx\ \ \ \ \ \ \ \ \ v=\frac{1}{4} e^{4x} \end{align*} Then \begin{align*} \int e^{4 x} d x&= \frac{1}{4} x^{2} e^{4 x}-\frac{1}{2} \int x e^{4 x} d x \end{align*} \begin{align*} u&= x \ \ \ \ \ \ \ \ \ dv= e^{4x}dx\\ du&= dx\ \ \ \ \ \ \ \ \ v=\frac{1}{4} e^{4x} \end{align*} Then \begin{align*} \int x e^{4 x} d x&=\frac{1}{4} x e^{4 x}-\frac{1}{4} \int e^{4 x} d x\\ &= \frac{1}{4} x e^{4 x}- \frac{e^{4 x}}{16} \end{align*} Hence \begin{align*} \int_{0}^{1} x^{2} e^{4 x} d x&= \frac{1}{4} x^{2} e^{4 x}-\frac{1}{8} x e^{4 x}+\frac{1}{32} e^{4 x}\bigg|_{0}^{1}\\ &=\frac{5}{32} e^{4}-\frac{1}{32} \end{align*}
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.