Functions Question 170

Question: $ \underset{x\to 0}{\mathop{\lim }},\frac{{e^{\tan x}}-e^{x}}{\tan x-x}= $

[EAMCET 1994; RPET 2001]

Options:

A) 1

B) $ e $

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

D) $ \frac{1}{2} $

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Answer:

Correct Answer: A

Solution:

$ \underset{x\to 0}{\mathop{\lim }},\frac{{e^{\tan x}}-e^{x}}{\tan x-x}=\underset{x\to 0}{\mathop{\lim }},\frac{e^{x}[{e^{\tan x-x}}-1]}{\tan x-x} $ $ =\underset{x\to 0}{\mathop{\lim }}e^{x},.\underset{x\to 0}{\mathop{\lim }}\frac{{e^{\tan x-x}}-1}{\tan x-x}=e^{0}\times 1=1 $ .