y=[2x(x-1)+1]/(x-1)
=2x(x-1)/(x-1)+1/(x-1)
=2x+1/(x-1)
=(2x-2)+2/(2x-2)+2
x>1
所以2x-2>0
所以y>=2√[(2x-2)*2/(2x-2)]+2=2√2+2
所以最小值=2√2+2