# Homework Help: Second partial derivative wrt x

1. Jul 15, 2014

### jonroberts74

I just need some clarification that this is fine

so I have

$$f_{x} = -2xe^{-x^2-y^2}cos(xy) -ysin(xy)e^{-x^2-y^2}$$

now, taking the second derivative

$$f_{xx} = [-2xe^{-x^2-y^2}+4x^2e^{-x^2-y^2}]cos(xy) - ysin(xy)[-2xe^{-x^2-y^2}]+2xe^{-x^2-y^2}sin(xy)y-cos(xy)e^{-x2-y^2}y^2$$

2. Jul 15, 2014

The very first $x$ in the first term shouldn't be there. Otherwise it looks fine.

3. Jul 15, 2014

### jonroberts74

oh yeah, on my paper I didnt have it but I typed it into this

thanks!