f(x,y)=e^2x(x+y^2+2y)中,令偏导数fx(X,Y)等于0的式子怎么写?

设f(x)=e的y次方,证明：（1）,f(x)f(y)=f(x+y) ,(2),f (x)/f(y)=f(x-y) y'-2y=(e^x)-x y=e^x y'=e^x 可以写成 y=f(x)与导数y=f'(x) y=x^2 y=2x 写成y=f(x)与导数y=f'(x) 求函数f(x,y)=e^x(x+2y+y^2)的极值 设f(x,y)=e^(x^2+y^2) 则 f（x,kx）=? y=(e^x-e^-x)/2 f(x+y,x-y)=(x^2-y^2)/2xy,求f(x,y)! 设f(x+y,x-y)=x^2-y^2,则f(x,y)= 若f(x+y,y/x)=x^2-y^2,则F(X,Y)= 已知f(x+y,y/x)=x^2-y^2,则f(x,y)= f(x+y,y/x)=x^2-y^2求f(x,y) f(x+y,y/x)=x^2-y^2,求f(x,y),详见里面 f(x+y,x-y)=2xy(x-y),求f(x,y) 求y''+2y'+y=e^-x/x的通解y''+2y'+y=（e^-x）/x x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 f(xy,x-y)=x^2+y^2+xy;f(x,y)/∂x;f(x,y)/∂y (X,Y) f(x,y)={12y^2,0 f(x+y)=f(x)+f(y)+2xy