Calculus: Early Transcendentals 9th Edition

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

Chapter 3 - Section 3.6 - Derivatives of Logarithmic Functions - 3.6 Exercises - Page 224: 55

Answer

$\frac{{dy}}{{dx}} = \frac{{2{x^{\ln x}}\ln x}}{x}$

Work Step by Step

$$\eqalign{ & y = {x^{\ln x}} \cr & {\text{using the logarithmic differentiation}} \cr & \ln y = \ln \left( {{x^{\ln x}}} \right) \cr & \ln y = \ln x\ln x \cr & \ln y = {\ln ^2}x \cr & {\text{Differentiate both sides with respect to }}x \cr & \frac{d}{{dx}}\left[ {\ln y} \right] = \frac{d}{{dx}}\left[ {{{\ln }^2}x} \right] \cr & \frac{1}{y}\frac{{dy}}{{dx}} = 2\ln x\left( {\frac{1}{x}} \right) \cr & {\text{Solve for }}\frac{{dy}}{{dx}} \cr & \frac{{dy}}{{dx}} = 2y\ln x\left( {\frac{1}{x}} \right) \cr & {\text{Substitute }}{x^{\ln x}}{\text{ for }}y \cr & \frac{{dy}}{{dx}} = 2{x^{\ln x}}\ln x\left( {\frac{1}{x}} \right) \cr & {\text{Simplify}} \cr & \frac{{dy}}{{dx}} = \frac{{2{x^{\ln x}}\ln x}}{x} \cr} $$
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.