y'=-2xy;求f(x).

y'=-2xy;求f(x). f(xy,x-y)=x^2-xy+y^2.求f(x,y) f(x+y,x-y)=(x^2-y^2)/2xy,求f(x,y)! f(x+y,x-y)=2xy(x-y),求f(x,y) 已知f(x+y)=f(x)+f(y)+2xy,求f(0) 设f(x+y,x-y)=x^2+xy,求f(x,y) f(2x+y,2y+x)=xy,求f(x,y) 函数f(xy,y^2/x)=x^2+y^2,求f(y^2/x,xy) 设F(xy,y^2/x)=x^2+y^2,求F（y^2/x,xy） 已知f(xy,（y^2）/x)=x^2+y^2,求f（（y^2）/x,xy） 已知f(xy,y^2/x)=x^2+y^2 求f(y^2/x,xy) f(x^2-y^2,x-y)=x+y+x^2-xy,求f'(x,y)对y求导 f(xy)=f(x)+f(y),f(8)=3,求f(√2), y'=-2xy;求f(x).y'=2y/x+2;求y 设函数f(xy,x+y)=x^2+y^2+xy,求∂f(x,y)／∂x和∂f(x,y)／∂y f(x+y)=f(x)+f(y)+2xy f'(0)=1,f(x+y)=f(x)+f(y)+2xy,求f(x) f(x)满足f(x+y)+f(xy)=2f(x)f(y)求函数的奇偶性