已知F(X+Y,X-Y)=X^2*Y+X*Y^2,则F(X,Y)=?

已知f(x+y,y/x)=x^2-y^2,则f(x,y)= 已知F(X+Y,X-Y)=X^2*Y+X*Y^2,则F(X,Y)=? 已知函数f(x+y,x-y)=x^2-y^2,则偏f(x,y)/偏x+偏f(x,y)/偏y=? 已知f(x)=3^x,求证：(1)f(x)·f(y)=f(x+y);(2)f(x)/f(y)=f(x-y). 已知函数f(x,y,z)=arcsin(x*x+y*y+lnz)求f(x-y,x+y,xz)? 已知f(0)=1,f(x-y)=f(x)-y(2x-y+1),求f(x) 已知：f(x+y)+f(x-y)=2f(x)*f(y),x.y取任何实数且f(0)不等于0,求证：f(x)为偶函数 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)= f(x+y,x-y)=(x^2-y^2)/2xy,求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) x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 二元函数f(x,y)=x+y/x-y,求f(y/x,x/y) 已知函数f(x)=3x,求证:f(x)+f(y)=f(x+y) f(xy,x-y)=x^2+y^2+xy;f(x,y)/∂x;f(x,y)/∂y 已知f(x,y)=x^2arctan(y/x)-y^2arctan(x/y)求它的混合二阶偏导