名校
1 . 已知公差不为零的等差数列
的前
项和为
,若
,且
成等比数列.
(1)求数列
的通项公式;
(2)若
,求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc91e27c7410472197be18c0ed2ebb3f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edcd9a1492c60152f2e32604cd519e72.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87045df56b97c4cc4f75f7cfda6f7a77.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/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
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2019-06-06更新
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1039次组卷
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11卷引用:云南省昭通市2017届高三复习备考统一检测(第二次)文科数学试题
云南省昭通市2017届高三复习备考统一检测(第二次)文科数学试题广东省广州市广东仲元中学2016-2017学年高一第二学期期末考试数学试题陕西省西安市第一中学2017-2018学年高二上学期第一次月考数学试题(已下线)2018年10月18日 《每日一题》人教必修5-(上学期期中复习)裂项相消法求和与分组法求和【全国百强校】宁夏石嘴山市第三中学2018-2019学年高二上学期第一次(10月)月考数学(文)试题安徽省巢湖第一中学2018-2019学年高二下学期第三次月考数学(文)试题新疆自治区北京大学附属中学新疆分校2018-2019学年高一下学期期中考试数学试题甘肃省白银市会宁县第一中学2019-2020学年高二上学期期中数学(文)试题广东省珠海市第二中学2018-2019学年高二上学期期中数学(理)试题北京市师大附中2022-2023学年高二上学期数学期末试题河南省温县第一高级中学2022-2023学年高二下学期第一次月考数学试题
2 . 已知数列
前n项的和为
且
,
.
(1)求证:数列
是等差数列;
(2)证明:当
时,
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de4a643e34e4fe80e2e44d73798bb50e.png)
(1)求证:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8050391385b496e9c059201e4f12600a.png)
(2)证明:当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0704f453b2de48d36911f7db496bbf82.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22631826d51a33fcb2cab97aa0015782.png)
您最近一年使用:0次
名校
解题方法
3 . 数列
是等差数列且
,
,数列
的前
项和为
,且
.
(1)求数列
,
的通项公式;
(2)求数列
的前n项和为
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18d8e8f821111de8075e5c3dfb22a5d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7da6e97248df8f138ebe684c40c950c7.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)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99cdaee634bd60340c038f68992c5f51.png)
(1)求数列
![](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/b52c9237cb0b4acc568d4afb12997186.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
您最近一年使用:0次
名校
4 . 设等差数列
满足
,
,其前
项和为
,若数列
也为等差数列,则
的最大值是( )
![](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/271f71c65d8206e4fae046b8beec427f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/832d1e3a06f59a35396aac6e12c5e2ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1cd633474e4022e53e42ecdfac6f0512.png)
A.100 | B.121 | C.132 | D.144 |
您最近一年使用:0次
2010·上海徐汇·二模
5 . 设数列
是等差数列,且公差为
,若数列
中任意(不同)两项之和仍是该数列中的一项,则称该数列是“封闭数列”.
(1)若
,判断该数列是否为“封闭数列”,并说明理由?
(2)设
是数列
的前
项和,若公差
,试问:是否存在这样的“封闭数列”,使
;若存在,求
的通项公式,若不存在,说明理由;
(3)试问:数列
为“封闭数列”的充要条件是什么?给出你的结论并加以证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b71661efbd38645dd04a5c93ed6bc32c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c02bc0c74292b1e8f395f90935d3174.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f069c238e1d9239fd3913b228965460f.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50c81d6206a09006901987c51d7532cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d54d6777bfac3060e53da2ff964e5b26.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(3)试问:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
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