宁波市行政区:已知x/(x^2+x+1)=1/3,求(x^2)/(x^4+x^2+1)的值

来源:百度文库 编辑:查人人中国名人网 时间:2024/05/04 15:43:35

x/(x^2+x+1)=1/3
=>1/(x+1+1/x)=1/3
=>x+1/x=2
=>(x+1/x)^2=4
=>(x^2+1/x^2)=4-2=2
所以
(x^2)/(x^4+x^2+1)
=1/(x^2+1/x^2+1)
=1/(2+1)
=1/3

解:
由x/(x^2+x+1)=1/3可知x=1;
代入所求式子:
(x^2)/(x^4+x^2+1)=1/3