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