Question

已知fx是定义在o,+oo上的增函数,且满足fxy=fx+fy,f2=1.1求f4与f8的值;

Answer 1

1、f(4)=f(2)+f(2)=2,f(8)=f(4)+f(2)=3

2、f(x)>f(x-2)+3

f(x)>f(x-2)+f(8)

f(x)>f(8(x-2))

x>8x-16

……