Calculus: Early Transcendentals 9th Edition

Published by Cengage Learning
ISBN 10: 1337613924
ISBN 13: 978-1-33761-392-7

Chapter 7 - Section 7.1 - Integration by Parts - 7.1 Exercises - Page 490: 10

Answer

$ - \frac{{\ln x}}{x} - \frac{1}{x} + C$

Work Step by Step

$$\eqalign{ & \int {\frac{{\ln x}}{{{x^2}}}} dx \cr & {\text{Integrating by parts}}{\text{, }} \cr & {\text{Let }}u = \ln x,{\text{ }}du = \frac{1}{x}dx \cr & {\text{ }}dv = \frac{1}{{{x^2}}}dx,{\text{ }}v = \frac{{{x^{ - 2 + 1}}}}{{ - 2 + 1}} = - {x^{ - 1}} = - \frac{1}{x} \cr & {\text{Using integration by parts formula}} \cr & \int u dv = uv - \int {vdu} \cr & \int {\left( {\ln x} \right)\left( {\frac{1}{{{x^2}}}} \right)} dx = \left( {\ln x} \right)\left( { - \frac{1}{x}} \right) - \int {\left( { - \frac{1}{x}} \right)\left( {\frac{1}{x}} \right)dx} \cr & {\text{Multiply}} \cr & \int {\frac{{\ln x}}{{{x^2}}}} dx = - \frac{{\ln x}}{x} + \int {\frac{1}{{{x^2}}}} dx \cr & {\text{Integrate using the power rule }}\int {{x^n}} dx = \frac{{{x^{n + 1}}}}{{n + 1}} + C, \cr & \int {\frac{{\ln x}}{{{x^2}}}} dx = - \frac{{\ln x}}{x} + \frac{{{x^{ - 2 + 1}}}}{{ - 2 + 1}} + C \cr & \int {\frac{{\ln x}}{{{x^2}}}} dx = - \frac{{\ln x}}{x} + \frac{{{x^{ - 1}}}}{{ - 1}} + C \cr & \int {\frac{{\ln x}}{{{x^2}}}} dx = - \frac{{\ln x}}{x} - \frac{1}{x} + C \cr} $$
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.