设n=0
f(m+0)=f(m)+f(0)-1=f(m)
f(0)=1
f(0)=f(1/2-1/2)=f(1/2)+f(-1/2)-1=1
f(1/2)=2
f(1/2)=f(1-1/2)=f(1)-1=2
f(1)=3
.
[f(x)-f(x-1/2)]=1
K=[f(x)-f(x-1/2)]/[x-(x-1/2)]=1/(1/2)=2
y=2x+1
f(x-1/2)=f(x)+f(-1/2)-1=f(x)-1
f(x)-f(x-1/2)=1
K=2>0
所以,直线递增
设n=0
f(m+0)=f(m)+f(0)-1=f(m)
f(0)=1
f(0)=f(1/2-1/2)=f(1/2)+f(-1/2)-1=1
f(1/2)=2
f(1/2)=f(1-1/2)=f(1)-1=2
f(1)=3
.
[f(x)-f(x-1/2)]=1
K=[f(x)-f(x-1/2)]/[x-(x-1/2)]=1/(1/2)=2
y=2x+1
f(x-1/2)=f(x)+f(-1/2)-1=f(x)-1
f(x)-f(x-1/2)=1
K=2>0
所以,直线递增