若x+1/x=3,则x方/(x四次+x方+1)的值为

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若x+1/x=3,则x方/(x四次+x方+1)的值为

若x+1/x=3,则x方/(x四次+x方+1)的值为
若x+1/x=3,则x方/(x四次+x方+1)的值为

若x+1/x=3,则x方/(x四次+x方+1)的值为
x+1/x=3
(x+1/x)²=3²
x²+1/x²+2*x*1/x=9
x²+1/x²+2=9
x²+1/x²=7
x方/(x四次+x方+1)
=1/(x四次/x²+x方/x²+1/x²)
=1/(x²+1+1/x²)
=1/(7+1)
=1/8

(x^2)/(x^4+x^2+1)=1/[x^2+1/(x^2)+1],又因为:x+1/x=3,所以(x+1/x)^2=3^2=9,所以:x^2+1/(x^2)+2=9,所以:x^2+1/(x^2)+1=9-1=8,代入得:(x^2)/(x^4+x^2+1)=1/[x^2+1/(x^2)+1]=1/8
望君采纳,谢谢~