已知函数f(x)满足f(x+y)+f(x-y)=2f(x)f(y)(x∈R,y∈R),且f(0)≠1.

已知函数f(x)满足f(x+y)+f(x-y)=2f(x)f(y)(x∈R,y∈R),且f(0)≠1. 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) 已知函数f（x）满足：对任意x，y∈R，都有f（x+y）=f（x）•f（y）-f（x）-f（y）+2成立，且x＞0时，f 已知函数f（x）满足f（x+y）+f（x-y）=2f（x）•f（y）  （x∈R，y∈R），且f（0 定义在R上的函数f(x)满足f (x + y) = f (x) + f ( y )(x,y∈R),当x>0时,f (x) 已知函数f(x)满足f(0)=1,且对x,y∈R,恒有f(x+y)+f(x-y)=2f(x)*cosy.求f(x) 有关函数的奇偶性已知f(x)定义在R上对任意x,y∈R,f(x+y)+f(x-y)=2f(x)*f(y),且f(0)≠0 定义域在R的单调函数f(x)满足f(x+y)=f(x)+f(y)(x,y∈R),且f(3)=6. 定义在R上的函数f(x)对任意x,y∈R都有f(x+y)+f(x-y)=2f(x)*f(y),且f（0）≠0,判断f（x 已知函数满足对任意xy属于R都有f(x+y)=f(x)*f(y)-f(x)-f(y)+2成立,且x2,证明x 已知函数f（x）对于任意的x,y∈R都满足f(x+y)=f(x)+f(y),且当x＞0时f(x)＞0恒成立 证明f(x) 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