已知x+1/x=2求4x²-7x+4/x²+2x+1

问题描述:

已知x+1/x=2求4x²-7x+4/x²+2x+1

x+1/x=2
x²+1=2x
x²-2x+1=0
(x-1)²=0
x=1
4x²-7x+4/x²+2x+1
=1-7+4/1+2+1
=-2/4
=-1/2