University Calculus: Early Transcendentals (3rd Edition)

Published by Pearson
ISBN 10: 0321999584
ISBN 13: 978-0-32199-958-0

Chapter 4 - Section 4.5 - Indeterminate Forms and L'Hôpital's Rule - Exercises - Page 249: 77

Answer

a) The limit provided in part(a) is not correct. b) The limit provided in part(b) is not correct. c) The limit provided in part(c) is not correct. d) The limit provided in part(d) is correct.

Work Step by Step

L'Hospital's rule states that $\lim\limits_{x \to \infty} f(x)=\lim\limits_{x \to \infty} \dfrac{A'(x)}{B'(x)}$ a) Here, $\lim\limits_{x \to 0^{+}} x \ln x\ne (0) (-\infty )=0$ Incorrect. b) Here, $\lim\limits_{x \to 0^{+}} x \ln x\ne (0) (-\infty )=-\infty$ Incorrect. c) Here,$\lim\limits_{x \to 0^{+}} x \ln x =\lim\limits_{x \to 0^{+}} \dfrac{\ln x}{1/x}\ne \dfrac{-\infty}{\infty}=-1$ Incorrect. d) Here, $\lim\limits_{x \to 0^{+}} x \ln x =\lim\limits_{x \to 0^{+}} \dfrac{\ln x}{1/x}=\lim\limits_{x \to 0^{+}} (-x) =0$ Correct.
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.