1. Find fxx, fxy, fyx, and fyy for the following function. (Remember, fSubscriptyx means to differentiate with respect to y and then with respect to x.)

f(x,y)=e8xy

2. Find fx and fy.

f(x,y)=-3e6x-7y

3. Find the four second-order partial derivatives for f(x,y)=6x4y7+7x5y6.

fxx=

fyy=