题目错了吧?应该是:x^2-3x+1=0,求:x^2+ 1/x^2
x^2-3x+1=0,
两边同除以X
得:x-3=1/x
化简后:X²+(X-3)²
再化简:X²+X²-6X+9
变形:X²-3X+X²-3X+9
把题目歼亮里告诉你的条件带进去:X²-3X=0
∴答案为9
如果不氏租宽是的话,也给你个启示型漏吧
-2-6x-1/(1+3x)
解:由雹纤x²-3x+1=0得:侍敬x²=3x-1,x+1/x=3,
则:x²+(x²+1/x²)=3x-1+(x+1/x)²-2
=3(x-1)+9
=3(x+2)
由x²-3x+1=0解源谈仿得:x1,x2=(3±sqar(5))/2,
则:x²+(x²+1/x²) =3(x+2)=(21±3sqar(5))/2