问题 解答题

已知x2-x+1=0,求代数式x8+x4+1的值.

答案

∵x2-x+1=0

∴x2=x-1,

∴x8+x4+1=x4(x4+1)+1

=(x22[(x22+1]+1,

=(x-1)2[(x-1)2+1]+1,

=(x2-2x+1)[(x2-2x+1)+1]+1,

=(x-1-2x+1)(x-1-2x+1+1)+1,

=(-x)(-x+1)+1,

=x2-x+1,

=0.

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