f(-1)=log2(1-(-1))=1
f(0)=log2(1-0)=0
f(1)=f(0)-f(-1)=-1
f(2)=f(1)-f(0)=-1
f(3)=f(2)-f(1)=0
f(4)=f(3)-f(2)=1
f(5)=f(4)-f(3)=1
f(6)=f(5)-f(4)=0
f(7)=f(6)-f(5)=-1
f(8)=f(7)-f(6)=-1
f(9)=f(8)-f(7)=0
f(10)=f(9)-f(8)=1
f(11)=f(10)-f(9)=1
f(12)=f(11)-f(10)=0
可见x>0时,f(x)的值以6为一个最小周期
2014÷6=335.4
所以f(2010)=-1
另证明：
f(x)=f(x-1)-f(x-2)
f(x-1)=f(x-2)-f(x-3)
f(x)=f(x-1)-f(x-2)=f(x-2)-f(x-3)-f(x-2)=-f(x-3)
f(x+3)=-f(x)
f(x+6)=f[(x+3)+3]=-f(x+3)=-[-f(x)]=f(x)
故f(x)周期为6