Calculus: Early Transcendentals 8th Edition

Published by Cengage Learning
ISBN 10: 1285741552
ISBN 13: 978-1-28574-155-0

Chapter 2 - Section 2.3 - Calculating Limits Using the Limit Laws - 2.3 Exercises - Page 102: 14

Answer

Does not exist

Work Step by Step

Simplify: $\frac{x²+3x}{x²-x-12}$ $\frac{x(x+3)}{(x-4)(x+3)}$ $\frac{x}{x-4}$ , x $\ne$ - 3 Check the left hand limit: $\lim\limits_{x \to 4^- }$ $\frac{x}{x-4}$ = $\frac{positivenumbercloseto4}{very small negative number}$ = - ∞ Check the right hand limit: $\lim\limits_{x \to 4^+ }$ $\frac{x}{x-4}$ = $\frac{positivenumbercloseto4}{very small positive number}$ = ∞ $\lim\limits_{x \to 4^- }$ $\ne$ $\lim\limits_{x \to 4^+ }$ The left and right hand limits are not equal therefore the limit does not exist. A graph of the function confirms the left and right limits don't match.
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.