Question:
Mark $(\sqrt{)}$ against the correct answer in the following:
If $y=\sqrt{\frac{\sec x-1}{\sec x+1}}$ then $\frac{d y}{d x}=?$
A. $\sec ^{2} \mathrm{x}$
B. $\frac{1}{2} \sec ^{2} \frac{\mathrm{x}}{2}$
C. $\frac{-1}{2} \operatorname{cosec}^{2} \frac{\mathrm{x}}{2}$
D. none of these
Solution:
