(x,y)=(x)^2-(y)^2-x-|||-__ B . (x,y)=(x)^2-(y)^2-x-|||-__C . (x,y)=(x)^2-(y)^2-x-|||-__D . (x,y)=(x)^2-(y)^2-x-|||-__

函数(x.y)=4x-(x)^2-(y)^2的极值为（ ）(x.y)=4x-(x)^2-(y)^2(x.y)=4x-(x)^2-(y)^2(x.y)=4x-(x

()-|||-A (x)=(x)^2-(y)^2+2xy+i((y)^2-(x)^2)-|||-B (x)=(x)^2-(y)^2+2xy+i((y)^2+2x

设=dfrac (2x)({x)^2-(y)^2} ，则 =dfrac (2x)({x)^2-(y)^2}=dfrac (2x)({x)^2-(y)^2}___

设 (x+y,x-y)=2((x)^2+(y)^2)(e)^(x^2-{y)^2}, 则 _(x)(x,y)-(f)_(y)(x,y)= __

[题目]设 (x-y,y|x)=(x)^2-(y)^2 求f(x,y)

1.求函数(x,y)=4(x-y)-(x)^2-(y)^2-|||-__的极值.1.求函数的极值.

(B) dfrac (x)(y)((y+1))^2-|||-(C) ^2((x+dfrac {1)(x))}^2. (D) dfrac (y)(x)((y+1)

[题目]-|||-求 (x,y)=4(x-y)-(x)^2-(y)^2 的极值

求函数 (x,y)=4(x-y)-(x)^2-(y)^2 的极值.

已知压和函数=(y)^2-(x)^2, 求解析函数 数=(y)^2-(x)^2 使得数=(y)^2-(x)^2已知压和函,求解析函数使得