已知X的平方-X+1分之X=6,求X四次方+X平方+1分之X的平方的值
人气：496 ℃ 时间：2019-08-19 23:45:27
解答
x/(x^2-x+1)=61/(x-1+1/x)=6x-1+1/x=1/6x+1/x=1+1/6=7/6(x+1/x)^2=49/36x^2+1/x^2+2=49/36x^2+1/x^2=49/36-2=-23/36x^2/(x^4+x^2+1)=1/(x^2+1+1/x^2)=1/{(x^2+1/x^2)+1}=1/(1-23/36)=36/(36-23)=36/13
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