Thomas' Calculus 13th Edition

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

Chapter 7: Transcendental Functions - Section 7.5 - Indeterminate Forms and L'Hopital's Rule - Exercises 7.5 - Page 409: 29

Answer

$\dfrac{1}{\ln 2}$

Work Step by Step

Let $\lim\limits_{x \to 0}f(x)=\lim\limits_{x \to 0}\dfrac{x 2^x}{2^x-1}$ But $f(0)=\dfrac{(0) 2^{0}}{2^{0}-1}=\dfrac{0}{0}$ This shows that the limit has an indeterminate form, so we need to apply L-Hospital's rule as follows: $\lim\limits_{m \to n}f(x)=\lim\limits_{m \to n}\dfrac{p'(x)}{q'(x)}$ This implies that $\lim\limits_{x \to 0}\dfrac{(2^x)+)(x) (2^x) (\ln 2)}{(2^x) (\ln 2)}=\dfrac{2^{0}+0}{2^{0} \ln 2}$ Thus, $\dfrac{1+0}{(1) \ln 2}=\dfrac{1}{\ln 2}$
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.