函数f(x,y)=x3-4x2+2xy-y2的极大值点是____.

函数f(x,y)=x3-4x2+2xy-y2的极大值点是____.
【正确答案】:{fx=3x2-8x=2y=0 fy=2x-2y=0 得: {x=0 y=0 即(0,0)