已知f(x+y)=f(x)乘以f(y),且f(x)不等于0,证明f(x)>0
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
若定义域为R函数f(x)满足f(x+y)=2*f(x)*f(y),且f(0)不等于0,证明f(x)是偶函数
求大侠来解已知在x.y不等于0时,f(x乘以y)=f(x)+f(y),且f(2)=1.求f(6)=?那f(1/2)不是等
函数f(x)对任意实数x,y有f(x+y²)=f(x)+2[f(y)]²,且f(1)不等于0,求f(
已知函数f(x+y)+f(x-y)=2f(x),且f(0)≠0,证明f(x)为偶函数
f(x+y)=f(x)f(y)且,x>0,f(x)属于(0,1)
已知函数f(x)满足f(x+y)+f(x-y)=2f(x)f(y),且f(0)不等于0,若f(π /2)=0,求f(π
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.
定义域在R上的函数f(x)对实数x,y,有f(x+y)+f(x-y)=2f(x)f(y),且f(0)不等于0.判断并证明
对所有实数x 、y ,若函数y=f(x),满足f(xy)=f(x)f(y),且f(0)不等于0,求f(2009)=( )
f(xy)=f(x)+f(y),证明f(x/y)=f(x)-f(y)
已知F(X*Y)=F(X)+F(Y)定义域为(0,正无穷大)且是增函数,求证F(X/Y)=F(X)-F(Y)