Calculus, 10th Edition (Anton)

Published by Wiley
ISBN 10: 0-47064-772-8
ISBN 13: 978-0-47064-772-1

Chapter 7 - Principles Of Integral Evaluation - 7.2 Integration By Parts - Exercises Set 7.2 - Page 498: 38

Answer

$$2\ln \left( 5 \right) - 4 + 2{\tan ^{ - 1}}2$$

Work Step by Step

$$\eqalign{ & \int_0^2 {\ln \left( {{x^2} + 1} \right)} dx \cr & {\text{substitute }}u = \ln \left( {{x^2} + 1} \right),{\text{ }}du = \frac{{2x}}{{{x^2} + 1}}dx \cr & dv = dx,{\text{ }}v = x \cr & {\text{applying integration by parts}}{\text{, we have}} \cr & \int_0^2 {\ln \left( {{x^2} + 1} \right)} dx = \left. {\left( {x\ln \left( {{x^2} + 1} \right)} \right)} \right|_0^2 - \int_0^2 {\left( {\frac{{2{x^2}}}{{{x^2} + 1}}} \right)dx} \cr & {\text{long division}} \cr & \int_0^2 {\ln \left( {{x^2} + 1} \right)} dx = \left. {\left( {x\ln \left( {{x^2} + 1} \right)} \right)} \right|_0^2 - \int_0^2 {\left( {2 - \frac{2}{{{x^2} + 1}}} \right)dx} \cr & {\text{integrating}} \cr & \int_0^2 {\ln \left( {{x^2} + 1} \right)} dx = \left. {\left( {x\ln \left( {{x^2} + 1} \right)} \right)} \right|_0^2 - \left. {\left( {2x - 2{{\tan }^{ - 1}}x} \right)} \right|_0^2 \cr & \int_0^2 {\ln \left( {{x^2} + 1} \right)} dx = \left. {\left( {x\ln \left( {{x^2} + 1} \right) - 2x + 2{{\tan }^{ - 1}}x} \right)} \right|_0^2 \cr & {\text{evaluate limits}} \cr & = \left( {2\ln \left( {{2^2} + 1} \right) - 2\left( 2 \right) + 2{{\tan }^{ - 1}}2} \right) - \left( {2\ln \left( {{0^2} + 1} \right) - 2\left( 0 \right) + 2{{\tan }^{ - 1}}0} \right) \cr & {\text{simplify}} \cr & = \left( {2\ln \left( 5 \right) - 4 + 2{{\tan }^{ - 1}}2} \right) - \left( 0 \right) \cr & = 2\ln \left( 5 \right) - 4 + 2{\tan ^{ - 1}}2 \cr} $$
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.