Calculus (3rd Edition)

Published by W. H. Freeman
ISBN 10: 1464125260
ISBN 13: 978-1-46412-526-3

Chapter 2 - Limits - 2.2 Limits: A Numerical and Graphical Approach - Exercises - Page 54: 43

Answer

$\displaystyle\lim_{x\rightarrow -2^-} \dfrac{4x^2+7}{x^3+8}=-\infty$ $\displaystyle\lim_{x\rightarrow -2^+} \dfrac{4x^2+7}{x^3+8}=\infty$ The limit does not exist

Work Step by Step

We have to estimate the limit: $\displaystyle\lim_{x\rightarrow -2\pm} \dfrac{4x^2+7}{x^3+8}$ Graph the function: Therefore we get: $\displaystyle\lim_{x\rightarrow -2^-} \dfrac{4x^2+7}{x^3+8}=-\infty$ $\displaystyle\lim_{x\rightarrow -2^+} \dfrac{4x^2+7}{x^3+8}=\infty$ As the left hand limit and the right hand limit are not equal, the limit of the function in -2 does not exist. The function tends to $-\infty$ when $x\rightarrow -2^-$ and to $\infty$ when $x\rightarrow -2^+$. There is a vertical asymptote $x=-2$.
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.