若{an}是等差数列,公差d≠0,a2,a3,a6成等比数列,则公比为 ______.
人气:477 ℃ 时间:2019-08-20 12:38:16
解答
∵a
2,a
3,a
6成等比数列,
∴a
32=a
2a
6,即(a
1+2d)
2=(a
1+d)(a
1+5),整理得d
2+2a
1d=0
∴d=-2a
1,
∴
=
=
=3
故答案为3.
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