x
--------------- = 2
x² - x + 1
1
--------------- = 2 (分子分母同处以x)
x - 1 + 1/x
1
--------------- = 2
(x + 1/x)-1
得x+1/x=3/2
x²
------------
x^4+x²+1
1
= ------------- (分子分母同处以x^2)
x^2+1+1/x^2
1
= ---------------
(x+1/x)^2-1
=1/(9/4-1)=4/5
x/(x^2-x+1)=2
(x^2-x+1)/x=1/2
x-1+1/x=1/2
x+1/x=3/2
(x^4+x^2+1)/x^2
=x^2+1+1/x^2
=(x+1/x)^2-1
=(3/2)^2-1
=5/4
所以原式=1/(5/4)=4/5
4/5