设x,y∈R,且xy≠0,则(x
设x,y∈R+且xy-(x+y)=1,则x+y的最小值为______.
①设x,y∈R+,且x+y+xy=2,求x+y的最小值.
若x,y∈R+,且2x+8y-xy=0,则x+y的最小值为( )
设y=f(x)(x∈R,且x≠0)对任意非零实数x,y,都有f(xy)=f(x)+f(y)成立
设x,y属于R+,且4/x+1/y=1则xy的最小值是-----
已知函数y=f(x)(x≠0)对于任意x,y∈R,且x,y≠0.满足f(xy)=f(x)+f(y)
设函数f(x)对任意xy∈R,都有f(x+y)=f(x)+f(y),且x>0,f(x)<0,f(1)=-2,Ⅰ证明F(X
已知x,y∈R+,且x+y=1,求证:xy+1xy≥174
已知x,y∈R,且2x+8y-xy=0,求x+y的最小值
设函数f(x)对任意xy∈R,都有f(x+y)=f(x)+f(y),且x>0,f(x)<0,f(1)=-2,...
设f(x)是R上的函数,且满足f(0)=1,且对x,y∈R都有f(x-y)=f(x)-y(2x-y+1),则f(x)的表
设函数f(x),x∈R,且x不等于0,对任意非零实数x,y,满足f(xy)=f(x)+f(y),求f(-1)