University Calculus: Early Transcendentals (3rd Edition)

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

Chapter 2 - Section 2.6 - Limits Involving Infinity; Asymptotes of Graphs - Exercises - Page 108: 60

Answer

$$\lim_{t\to0^+}\Big(\frac{1}{t^{3/5}}+7\Big)=\infty$$ $$\lim_{t\to0^-}\Big(\frac{1}{t^{3/5}}+7\Big)=-\infty$$

Work Step by Step

(a) $$A=\lim_{t\to0^+}\Big(\frac{1}{t^{3/5}}+7\Big)=\lim_{t\to0^+}\frac{1+7t^{3/5}}{t^{3/5}}$$ As $t\to0^+$: $t^{3/5}\to0^+\gt0$ $(1+7t^{3/5})\to1^+\gt0$ So $\frac{1+7t^{3/5}}{t^{3/5}}\gt0$, and the function will approach $\infty$. Therefore, $$A=\infty$$ (b) $$B=\lim_{t\to0^-}\Big(\frac{1}{t^{3/5}}+7\Big)=\lim_{t\to0^-}\frac{1+7t^{3/5}}{t^{3/5}}$$ As $t\to0^-$: $t^{3/5}\to0^-\lt0$ $(1+7t^{3/5})\to1^-\gt0$ So $\frac{1+7t^{3/5}}{t^{3/5}}\lt0$, and the function will approach $-\infty$. Therefore, $$B=-\infty$$
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.