已知a^2-4a+1=0,求a^2/(a^4+1)

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已知a^2-4a+1=0,求a^2/(a^4+1)
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已知a^2-4a+1=0,求a^2/(a^4+1)
已知a^2-4a+1=0,求a^2/(a^4+1)

已知a^2-4a+1=0,求a^2/(a^4+1)
a^2-4a+1=0
a^2+1=4a
a^4+2a^2+1=16a^2
a^4+1=14a^2
所以a^2/(a^4+1)
=a^2/14a^2
=1/14

a^2-4a+1=0
a-4+1/a=0 两边除以a
a+1/a=4
两边平方得
a² +2+1/a²=16
a²+1/a²=14
(a的4次方+1)/a²=14
∴a^2/(a^4+1)=1/14

答:
a^2-4a+1=0
两边同除以a得:a-4+1/a=0
a+1/a=4
a^2/(a^4+1)
=1/(a^2+1/a^2) 分子分母同时除以a^2
=1/[(a+1/a)^2-2]
=1/(4^2-2)
=1/(16-2)
=1/14