已知a^2+3a-1 =0求a^8-3a^4+1/a^4的值

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已知a^2+3a-1=0求a^8-3a^4+1/a^4的值已知a^2+3a-1=0求a^8-3a^4+1/a^4的值已知a^2+3a-1=0求a^8-3a^4+1/a^4的值a^2+3a-1=0a^2

已知a^2+3a-1 =0求a^8-3a^4+1/a^4的值
已知a^2+3a-1 =0求a^8-3a^4+1/a^4的值

已知a^2+3a-1 =0求a^8-3a^4+1/a^4的值
a^2+3a-1 =0
a^2-1 =-3a(平方)
(a^2-1)^2 =9a^2
a^4-2a^2+1 =9a^2
a^4+1 =11a^2(平方)
(a^4+1 )^2=121a^4
a^8+2a^4+1=121a^4
a^8+2a^4+1-5a^4=121a^4-5a^4
a^8-3a^4+1=116a^4
(a^8-3a^4+1)/a^4=116