问题
填空题
已知x2+x+1=0,求值:x8+x4+1=______.
答案
∵x2-x+1=0
∴x2=-x-1,
∴x8+x4+1=x4(x4+1)+1
=(x2)2[(x2)2+1]+1
=(-x-1)2[(-x-1)2+1]+1
=(x2+2x+1)[(x2+2x+1)+1]+1
=(x+0)(0+x+1)+1
=(x)(x+1)+1
=x2+x+1
=0.
故答案为0.
已知x2+x+1=0,求值:x8+x4+1=______.
∵x2-x+1=0
∴x2=-x-1,
∴x8+x4+1=x4(x4+1)+1
=(x2)2[(x2)2+1]+1
=(-x-1)2[(-x-1)2+1]+1
=(x2+2x+1)[(x2+2x+1)+1]+1
=(x+0)(0+x+1)+1
=(x)(x+1)+1
=x2+x+1
=0.
故答案为0.