Question:
Mark $(\sqrt{)}$ against the correct answer in each of the following:
$\int \frac{\operatorname{cosec}^{2} x}{\left(1-\cot ^{2} x\right)} d x=?$
A. $\frac{1}{2} \log \left|\frac{1+\cot x}{1-\cot x}\right|+C$
B. $-\frac{1}{2} \log \left|\frac{1+\cot x}{1-\cot x}\right|+C$
C. $\frac{1}{2} \log \left|\frac{1-\cot x}{1+\cot x}\right|+C$
D. none of these
Solution: