若x1、x2是一元二次方程3x2+x-1=0的两个根,则(1x1)2+(1x2)2=______

若x1、x2是一元二次方程3x2+x-1=0的两个根,则(1x1)2+(1x2)2=______.
2025-02-25 22:33:27
推荐回答(1个)
回答1:

根据题意得x1+x2=-
1
3
,x1?x2=-
1
3

(
1
x1
)2
+(
1
x2
)2
=
x12+x22
x12?x22
=
(x1+x2)2?2x1x2
(x1x2)2
=
(?
1
3
)2?2×(?
1
3
)
(?
1
3
)2
=7.
故答案为7.