Question:
Mark $(\sqrt{)}$ against the correct answer in the following:
If $\mathrm{x}=\mathrm{a} \cos ^{2} \theta, \mathrm{y}=\mathrm{b} \sin ^{2} \theta$ then $\frac{\mathrm{dy}}{\mathrm{dx}}=$ ?
A. $\frac{-a}{b}$
B. $\frac{-\mathrm{a}}{\mathrm{b}} \cot \theta$
C. $\frac{-b}{a}$
D. none of these
Solution:
