Thomas' Calculus 13th Edition

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

Chapter 10: Infinite Sequences and Series - Section 10.1 - Sequences - Exercises 10.1 - Page 570: 72

Answer

converges to $1$

Work Step by Step

As we know that when $x \gt 0$ so, $\lim\limits_{n \to \infty} (1+\dfrac{x}{n})^{n}=e^x$ Let $\lim\limits_{n \to \infty} a_n= \lim\limits_{n \to \infty} (1-\dfrac{1}{n^2})^n$ But $ \lim\limits_{n \to \infty} (1-\dfrac{1}{n^2})=\lim\limits_{n \to \infty} \dfrac{\ln (1-\dfrac{1}{n^2})}{(1/n)}=\dfrac{0}{0}$ This shows that the limit has an Indeterminate form, so we will use L-Hospital's rule. This implies that $\lim\limits_{n \to \infty} (1-\dfrac{1}{n^2})=\lim\limits_{n \to \infty} \dfrac{-2n}{n^2-1}=0$ Thus, $\lim\limits_{n \to \infty} a_n= \lim\limits_{n \to \infty} (e)^{(n \ln n) (1-\dfrac{1}{n^2})}=e^0=1$ Hence, $\lim\limits_{n \to \infty} a_n=1$ and {$a_n$} converges to $1$.
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.