Question: Mark $(\sqrt{)}$ against the correct answer in the following:
If $y=\cos ^{-1} x^{3}$ then $\frac{d y}{d x}=?$
A. $\frac{-1}{\sqrt{1-\mathrm{X}^{6}}}$
B. $\frac{-3 x^{2}}{\sqrt{1-x^{6}}}$
C. $\frac{-3}{x^{2} \sqrt{1-x^{6}}}$
D. none of these
Solution:
