y=f(x)={(x-1)/(x+1)}^2,反函数f^-1(x)=(1+√x)/(1-√x),g(x)=(1-√x)/(1+√x))}+√x +2=(1+√x)+2/(1+√x)>=2√〔(1+√x)*2/(1+√x)〕=2√2,当(1+√x)=2/(1+√x),即x=3±2√2时,等号成立,ymin=2√2...