Hi I'm having trouble with the critical points.

f(x,y) = 2x^3 + 2y^3 - 9x^2 + 3y^2 - 12

fx = 6x^2 - 18x

0 = 6x^2 - 18x

x = 0 and 3

fy = 6y^2 + 6y

0 = 6y^2 + 6y

y = 0 and -1

Here is where i get stuck. I'm not sure what values of y to use for the x intercepts.

Could anyone show me what the critcal points are.