Question

Find all the local maxima, local minima, and saddle points of the function:
f(x,y) = 2xy-5x^2-2y^2+4x+4y-4

Answer 1

I know the partial derivatives are:
fx = 2y-10x+4
fy = 2x-4y+4

Answer 2

And to find the Critical points, i just set them equal to zero, but ikeep getting something other than what am suppose to get.