Calculus: Early Transcendentals 9th Edition

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

Chapter 2 - Section 2.6 - Limits at Infinity; Horizontal Asymptotes - 2.6 Exercises - Page 138: 32

Answer

$\lim\limits_{x \to \infty}(x-\sqrt{x})=\infty$

Work Step by Step

$\lim\limits_{x \to \infty}(x-\sqrt{x})=\lim\limits_{x \to \infty}(x-\sqrt{x})\times \frac{x+\sqrt{x}}{x+\sqrt{x}}$ $=\lim\limits_{x \to \infty}\frac{x^2-x}{x+\sqrt{x}}$ $=\lim\limits_{x \to \infty}\frac{x^2-x}{x+\sqrt{x}}\times \frac{1/x}{1/x}$ $=\lim\limits_{x \to \infty}\frac{x-1}{1+1/\sqrt{x}}$ (Use the properties of limits) $=\frac{\lim\limits_{x \to \infty}x-\lim\limits_{x \to \infty}1}{\lim\limits_{x \to \infty}1+\lim\limits_{x \to \infty}1/\sqrt{x}}$ (Use the limits $\lim\limits_{x \to \infty}x=\infty$ and $\lim\limits_{x \to \infty}1/\sqrt{x}=0$) $=\frac{\infty-1}{1+0}$ $=\frac{\infty-1}{1}$ $=\infty$ Thus, $\lim\limits_{x \to \infty}(x-\sqrt{x})=\infty$.
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.