Calculus: Early Transcendentals 9th Edition

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

Chapter 11 - Section 11.4 - The Comparison Tests - 11.4 Exercises - Page 731: 13

Answer

Diverges

Work Step by Step

We know that for all $\ln n < n$ for all $n\geq 2$. We have now $\frac{1}{\ln n}>\frac{1}{n}$ since the left side has a smaller denominator. Since $\sum_{n=2}^\infty \frac{1}{n}$ is a divergent $p-$series with $p=1$, it follows by the Direct Comparison Test with $a_n=\frac{1}{\ln n}$ and $b_n=\frac{1}{n}$ that the series $\sum_{n=2}^\infty\frac{1}{\ln n}$ diverges.
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.