Hi guys, Please could someone check the following for me, I have no confidence at all with calculus. have bought three books to day to finally get to grips with it, but these are due before then.

Many thanks in advance.

If: z = e^x . Cos (xy) Find the partials for x and x, and second order partial for y.

I have dz/dx = e^x . y - sin (xy) dz/dy = e^x . x - sin (xy)

And

d/dy * dz/dy = d^2 z/ dy^2 = e^x . x^2 . cos (xy)