Hey I was wondering if anyone can tell me if i am doing this right. f(x,y) = xy^2 ; R is the circular disk x^2+y^2<=3 So first i took the gradient, since I know a mix/min can exist if the gradient is equal to 0. Gradient of X= y^s Gradient of Y= 2xy So the point (0,0) can be considered right? Anyway, I know I have to test region edges, so I parameterized the equation. r(t) = <radical 3 cos(t),radical 3 sin(t)> i plugged those values of x and y into my equation , and then took the derivative. After some simplification, I came up with sin(t)(3*radical3*cos(t)^2-3*radical3) t= 0, pi, pi/2, 3pi/2 (right?) so i found the x and y value when t is equal to those values in conclusion, i have these points. (0,0) (0,radical3) (0,-radical3) (radical3,0) (-radical3,0) I tested these values in the equation xy^2 = f(x,y) and found that there is no max or min....i dont think this is right. Can someone help me find my mistake?