2013·江西南昌·二模
1 . 已知各项均不相等的等差数列
的前三项和为18,
是一个与
无关的常数,若
恰为等比数列
的前三项,
(1)求
的通项公式.
(2)记数列
,
的前三
项和为
,求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d737c1047a14cee12a6671383e244fa5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4140357d6947ea73869e3acb257ae516.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2df98ce180b9d9e1a83f2c1332e2da9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a89d1f32c1605cfdb8e8855051b9f6ec.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a89d1f32c1605cfdb8e8855051b9f6ec.png)
(2)记数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff79c81c77e8252c89bddc8104c4e1cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c522c1c881528ab6f9708f6bdd4c4db5.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/aaaf65af465633678a3ac65236d0de0f.png)
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11-12高二上·辽宁营口·期末
名校
2 . 设数列
是公比大于1的等比数列,
为数列
的前
项和,已知
,且
构成等差数列.
(I)求数列
的通项公式;
(II)令
…,求数列
的前n项的和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ccdc17b603871d20843ffccca2df0ae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0415f89c286a4a35364c5715a2a1b60.png)
(I)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
(II)令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83de708fcdee8570c924565125979f18.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f329b217e1051b23f0d61023cdc6e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
您最近一年使用:0次
2016-11-30更新
|
1415次组卷
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7卷引用:2012届广东揭阳一中、潮州金山中学高三第三次模拟考试理科数学试卷
(已下线)2012届广东揭阳一中、潮州金山中学高三第三次模拟考试理科数学试卷(已下线)2013届广东省揭阳一中高三上学期第二次段考数学试卷(已下线)2014届四川省成都七中高三三诊模拟文科数学试卷(已下线)2010—2011学年辽宁省营口市普通高中高二上学期期末教学质量检测理科数学2016届四川省绵阳市南山中学高三下学期入学考试文科数学试卷北京市顺义区牛栏山第一中学2019-2020学年高三上学期期中数学试题河南省郑州市八校2020-2021学年高二上学期期中联考数学(文)试题
2011·新疆·一模
名校
3 . 已知1、
、
、9成等差数列,1、
、
、
、9成等比数列,且
、
、
、
、
都是实数,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57b8ac5e02a7b900e0d62593e752f231.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/b715e7842b95f654f16056a7c7f2abe9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13423c094861baf4b759b7f3d8c3c226.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57483e04fd1840c87ac5325157149877.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/b715e7842b95f654f16056a7c7f2abe9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13423c094861baf4b759b7f3d8c3c226.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57483e04fd1840c87ac5325157149877.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57b8ac5e02a7b900e0d62593e752f231.png)
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2016-11-30更新
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1281次组卷
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4卷引用:2011届新疆农七师高级中学高三第一次模拟考试数学文卷
(已下线)2011届新疆农七师高级中学高三第一次模拟考试数学文卷河南省南阳市第一中学校2021-2022学年高二上学期第一次月考数学试题(已下线)第03讲 等比数列及其前n项和 (高频考点—精讲)-2河南省南阳市唐河县唐河县第一高级中学2022-2023学年高二下学期3月月考数学试题