# Question #f7644

$y$ is a constant with respect to $x$, so the derivative of log (xy) is $y \frac{1}{x}$
The derivative of $\log x$ is $\frac{1}{x}$, and since $y$ is a constant with respect to $x$, the derivative of $x y$ is $y$. Then the chain rule gives: the derivative of log (xy) is $y \frac{1}{x}$