1 . 有穷数列
满足
,且
成等比数列.若
,则满足条件的不同数列
的个数为________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a4a7fe19307bea082a669ae2269017a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5771cdf6cb1557e3772648a8bea28eb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a84be6c52f27e8c1920617fe927de35c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fad2c794af11169f2e277861aefefc93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
您最近一年使用:0次
2023-07-03更新
|
217次组卷
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2卷引用:重庆市南岸区2022-2023学年高二下学期期末数学试题
名校
2 . 已知三个数成等比数列,它们的和等于14,积等于64,则这个等比数列的公比是( )
A.2或![]() | B.2或![]() | C.![]() ![]() | D.![]() ![]() |
您最近一年使用:0次
名校
解题方法
3 . 已知
是公差不为零的等差数列,
,且
成等比数列.
(1)求数列
的通项;
(2)设数列
,求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2df98ce180b9d9e1a83f2c1332e2da9.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)设数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e44e8d0669e5bb98993cb10e0e7899b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
您最近一年使用:0次
2020-02-21更新
|
452次组卷
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3卷引用:重庆市广益中学2019-2020学年高一下学期5月月考数学试题