Q55 / 155 · WBJEE 2022 · Mathematics
$\lim _{x \rightarrow 0}\left(\frac{1}{x} \ln \sqrt{\frac{1+x}{1-x}}\right)$ is
- A$1 / 2$
- B0
- Correct answerC1
- Ddoes not exist
Solution
$\lim _{x \rightarrow 0} \frac{1 / 2(\ln (1+x)-\ln (1-x))}{x}$
$=\frac{1}{2} \lim _{x \rightarrow 0}\left(\frac{1}{1+x}+\frac{1}{1-x}\right)=1$
Hence, the correct answer is option: 'C'.