Question: Mark $(\sqrt{)}$ against the correct answer in the following:
If $y=\tan ^{-1}\left(\frac{1-\cos x}{\sin x}\right)$ then $\frac{d y}{d x}=?$
A. 1
B. $-1$
C. $\frac{1}{2}$
D. $\frac{-1}{2}$
Solution:
Given that $y=\tan ^{-1}\left(\frac{1-\cos x}{\sin x}\right)$
