先阅读,在解答 阅读:若x^2/x^4+x^2+1=1/4,求x+1/x的值
问题描述:
先阅读,在解答 阅读:若x^2/x^4+x^2+1=1/4,求x+1/x的值
例子:若x+1/x=3
则(x+1/x)²=9
x²+1/x²=7
所以x²/(x^4+x²+1)
=1/(x²+1+1/x²)
=1/(7+1)
=1/8
答
令 x+1/x=t 则(x+1/x)²=t²=x²+1/x²+2 =>x²+1/x²=t²-2
x²/(x^4+x²+1)
=1/(x²+1+1/x²)=1/(t²-2+1)=1/(t²-1) = 1/4 => t²-1=4 =>t²=5 => t=±√5 .ans对不起你是对的