分两种情况讨论
x²-2x-1>=0 (1) x²-2x-1<=0
x-1>0 (2) x-1<0
(1)得
x²-2x+1-2>=0
(x-1)²-2>=0
(x-1+√2)(x-1-√2)>=0
x<=1-√2 或 x>=1+√2 1-√2<=x<=1+√2
(2)得 x>1 x<1
∴x>=1+√2 1-√2<=x<1
∴解集是x>=1+√2 或 1-√2<=x<1