I think I'm supposed to find the partial derivative of the equation with respect to x and then with respect to y, right?

The Problem is...

Find the slope of the line that is parallel to the (a)xz-plane (b)yz-plane and tangent to the surface $\displaystyle z=xln(x+y^2)$ at the point $\displaystyle P(e,0,e)$

I just don't know how to find the partial derivatives of $\displaystyle z=xln(x+y^2) $