1. The problem statement, all variables and given/known data 3. The attempt at a solution So I am trying to find the gradient because in class we were taught that the surface area is the magnitude of the gradient divided by the magnitude of the dot product between the gradient and normal to the projected surface. I noticed in the textbook, the solution uses some sort of vector r_u and r_v, however this was not covered in class so I am somewhat confused. Is it possible to do this problem with just the knowledge I know?