Functions Question 227

Question: $ \underset{x\to 1}{\mathop{\lim }},\frac{1+\log x-x}{1-2x+x^{2}}= $

[Karnataka CET 2000; Pb. CET 2001]

Options:

A) 1

B) ?1

C) 0

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

Show Answer

Answer:

Correct Answer: D

Solution:

Applying L-Hospital?s rule, $ \underset{x\to 1}{\mathop{lim}},\frac{1+\log x-x}{1-2x+x^{2}}=\underset{x\to 1}{\mathop{lim}},\frac{\frac{1}{x}-1}{-2+2x}=\underset{x\to 1}{\mathop{lim}},\frac{1-x}{2x(x-1)} $ Again applying L-Hospital?s rule, $ \underset{x\to 1}{\mathop{lim}},\frac{-1}{4x-2}=-\frac{1}{2} $ .