设公比为整数的等比数列
满足
,
.
(1)求
的通项公式;
(2)令
,记
为数列
的前
项和,若
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/111c884a9c22c6902353b7b4f7be7c5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1df7f2beffd703583d4b4db720bf778b.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
(2)令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09c926c37e5c95a4b67eb4e342dfee05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43b7e7cd571c8cd141cbbfe5d0890bf6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/26cda28972dd0a0d522a9b0e3283a856.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
2021·辽宁葫芦岛·二模 查看更多[3]
更新时间:2021-06-02 08:41:33
|
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【推荐1】已知数列
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(1)求数列
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(2)若
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
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(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
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(2)若
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
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【推荐2】淮安市2019年新建住房面积为500万
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35c901bcdfa58f0c68ad0161b0bab269.png)
(2)是否存在连续两年,每年所建安置房面积占当年新建住房面积的比保持不变?并说明理由.
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【推荐1】若分别从下表的第一、二、三列中各取一个数,依次作为等比数列{
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的
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(1)请写出数列{
},{
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}的前n项和为
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c1ccc6c74b8754e9bcbb3f39a11b6f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b715e7842b95f654f16056a7c7f2abe9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13423c094861baf4b759b7f3d8c3c226.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57483e04fd1840c87ac5325157149877.png)
第一列 | 第二列 | 第三列 | |
第一行 | 1 | 4 | 7 |
第二行 | 3 | 6 | 9 |
第三行 | 2 | 5 | 8 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/686ece75006ad358f23314dc8a246e11.png)
(2)若数列{
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/686ece75006ad358f23314dc8a246e11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3af57d1e002085c570f18f021858da68.png)
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您最近一年使用:0次
【推荐2】已知数列
是首项为2的等比数列,且
是
和
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(1)求
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(2)若数列
的公比
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满足
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daf464629fa321a6ff7401ab79f07083.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4e2d08cb0cbd07edb93dc2f9c7ed390.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c1ccc6c74b8754e9bcbb3f39a11b6f1.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
(2)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf3783e69ef5a6a0af566ff4e21ccf03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f71acdb04454c77e1e25ad4f336cccfe.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d383849f5a0c655077c97e69c73a93e.png)
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您最近一年使用:0次
解答题-问答题
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较易
(0.85)
名校
解题方法
【推荐1】已知
为等差数列,
是公比为正数的等比数列,
,
,
.
(1)求
和
的通项公式;
(2)求数列
的前n项和.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c5a7a17a394e868e0acd1803a9ab795.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b6e6f05768f3465ddaea277a6d33c59.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/375f596b59d4af5eef0b508a262675c6.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ec12a9a60f82467bf7bf834a9a9b1f7.png)
您最近一年使用:0次
解答题-问答题
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较易
(0.85)
解题方法
【推荐2】在各项均为负的等比数列
中,
,且
.
(1)求数列
的通项公式;
(2)
是否为该数列的项?若是,为第几项?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fe7cbb3cc1ec103ea3e067a9b6bd4a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd545febb302f8112ae482c64c8e1195.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/925b766814e8f33259d43426ce236a0b.png)
您最近一年使用:0次