Question

Examine the function for relative extrema:

z=x^2+xy+1/2y^2-2x+y

Answer 1

My question is how are they getting critical points of (3,-4) in their solution, everything else I've been able to get.

Answer 2

what math is this?. if multi like i expect. differentiate ;)

Answer 3

what is your specific question. they differentiate to get f_x (df/dx) and f_y (df/dy)