x²-2x-1=0
除以x得x-2-1/x=0
∴x-1/x=2
(1)x²+1/x²
=(x-1/x)²+2
=2²+2
=6
(2)(x的四次方+x²+1﹚÷x²
=x²+1+1/x²
=6+1
=7
∴x²/x的四次方+x²+1=1/7