# If $x^y=y^x$. then $x(x-y \log x) \large\frac{dy}{dx}$ is equal to :

$\begin {array} {1 1} (a)\;y(y- x \log y) & \quad (b)\;y(y+ x \log y)\\ (c)\;x(x+y \log x) & \quad (d)\;x(y-x \log y) \end {array}$

$(a)\;y(y- x \log y)$
answered Nov 7, 2013 by