f(x)对于任意实数x,y满足f(x+y)=f(x)+f(y),当x>0时,f(x)
问题描述：
f(x)对于任意实数x,y满足f(x+y)=f(x)+f(y),当x>0时,f(x)
答
hehe~f(0+0)=f(0)+f(0) so f(0)=2f(0)so f(0)=0f(x+(-x))=f(x)+f(-x)=f(0)=0so f(x)+f(-x)=0so f(x)=-f(x)(so 奇函数)设x1>x2>0f(x1-x2)=f(x1)+f(-x2)=f(x1)-f(x2)x1-x2>0so f(x1-x2)