Functions Question 271

Question: $ \underset{x\to \infty }{\mathop{\lim }},{{( \frac{x+3}{x+1} )}^{x+1}}= $

[RPET 2003, UPSEAT 2003]

Options:

A) $ e^{2} $

B) $ e^{3} $

C) e

D) $ {e^{-1}} $

Show Answer

Answer:

Correct Answer: A

Solution:

$ \underset{x\to \infty }{\mathop{\lim }},{{( \frac{x+3}{x+1} )}^{x+1}} $ $ =\underset{x\to \infty }{\mathop{\lim }},{{( 1+\frac{2}{x+1} )}^{\frac{x+1}{2}.2}} $ $ ={{{ \underset{x\to \infty }{\mathop{\lim }},{{( 1+\frac{2}{x+1} )}^{\frac{x+1}{2}}} }}^{2}} $ $ =e^{2} $ .