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