这里用递归定义,
f1(x)=f(x),fn+1(x)=f(fn(x)),
令n=1得f2(x)=f[f1(x)]=f[(x-√3)/(√3x+1)]
=[(x-√3)/(√3x+1)-√3]/{√3[(x-√3)/(√3x+1)]+1}
=[-2x-2√3]/{2√3x-2}(分子分母都乘以√3x+1)
=-(x+√3)/(√3x-1),
还有疑问吗?
这里用递归定义,
f1(x)=f(x),fn+1(x)=f(fn(x)),
令n=1得f2(x)=f[f1(x)]=f[(x-√3)/(√3x+1)]
=[(x-√3)/(√3x+1)-√3]/{√3[(x-√3)/(√3x+1)]+1}
=[-2x-2√3]/{2√3x-2}(分子分母都乘以√3x+1)
=-(x+√3)/(√3x-1),
还有疑问吗?