Find the extremum of function f (x, y) = x × x × X-Y × y × y + 3 × x × x + 3 × y × y-9x

Find the extremum of function f (x, y) = x × x × X-Y × y × y + 3 × x × x + 3 × y × y-9x

In this paper, we are going to get the X-1 (x-1) (x + 3) from F'x = 0 to get x = 1, from F'x = 0 to get x = 1, from F'x = 0 to get x = 1, from F'x = 0 to get x = 1, and from F'y = 0 to get x = 1, from F'x = 0 to get x = 1, and from F'x = 0 to get x = 1, from F'x = 0 to get x = 1, and from F'y-3 and from F'y = 0 to get y = 0, and from F'y = 0 to get y = 0, and from F'y (Y-3) to get y = 0, and from F'y = 0 to get y = 0, and let 2A = f "XX = 6x = 6x = 6x = 6x-6x + 6x + 6x + 6x-6x-6x + 6x-6b = 6x-6b = 6x-6b = 6x-ා178; > 0, a > 0