What is the second derivative of

Question

f(x,y) = 3x^2y + 4y^3 first with respect to y and then with respect to x?

Answer 1

d ( ))/dx=6xy+3x^2 dy/dx+12y^2 dy/dx

and

d( )/dy= 6ydx/dy+6x+ 12y^2

check my thinking.