[题目]设 (x-y,y|x)=(x)^2-(y)^2 求f(x,y)

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

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】-|||-求函数 =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.

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

【题目】21.设y=y(x)是由方程2y-x=(x-y)ln(x-y)确定的隐函数,求dy.【题目】21.设y=y(x)是由方程2y-x=(x-y)ln(x-y

[题目]-|||-求函数 (x,y)=(({x)^2+(y)^2)}^2-2((x)^2-(y)^2) 的极值.

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

设=dfrac (y)(f({x)^2-(y)^2)},其中f为可导函数.验证=dfrac (y)(f({x)^2-(y)^2)}.设,其中f为可导函数.验证.

证明u(x,y)=(x-y)(x^2+4 xy+y^2)u(x,y)=(x-y)(x^2+4 xy+y^2)u(x,y)=(x-y)(x^2+4 xy+y^2)