1 . 设等差数列
的前
项和为
,若
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/614306cc3f34bdee4d5d885b79667645.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.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/43076b5b0ad39d752a906a9c2c5c6673.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/614306cc3f34bdee4d5d885b79667645.png)
A.0 | B.![]() |
C.4 | D.1 |
您最近一年使用:0次
2017-04-01更新
|
530次组卷
|
2卷引用:2017届河北省曲周县第一中学高三下学期第一次模拟考试文数试卷
名校
2 . 已知数列
满足
,
,
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3f7fda69e2b32b9ced2239f915fa59b.png)
____ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ffa01f03fb074bff35b35e07047d11b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14835bf3f00139ccec0694d0924db795.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/961453a6914e096737b9d8125bb003bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3f7fda69e2b32b9ced2239f915fa59b.png)
您最近一年使用:0次
3 . 一个数列的前n项之和为
,那么它的第n项为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/366fcb4e6ecb4335255dfee26f0d298e.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
您最近一年使用:0次
4 . 等差数列
中,
,则
中的最大值是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20937f23a4445471e6851458fc8558e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
A.![]() | B.![]() ![]() | C.![]() | D.![]() |
您最近一年使用:0次
10-11高一下·河北邯郸·期末
5 . 设数列
的前
项和为
,已知![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b29b9163edc85cbbce9679bc175bb3a7.png)
(1)设
证明数列
是等比数列;
(2)求数列
的通项公式;
(3)求
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/b29b9163edc85cbbce9679bc175bb3a7.png)
(1)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/678fc75b118f4b45e27989f87a85acdf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(3)求
![](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)
您最近一年使用:0次
6 . 设数列
的前
项和为
,且
,若
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7999465d0e871febde66296a0cbf058c.png)
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.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/33bcf3110dfc47b63ca9b917e18fdee8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a316124e688e76d6f330ffbea49d427d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7999465d0e871febde66296a0cbf058c.png)
您最近一年使用:0次
2017-03-07更新
|
904次组卷
|
2卷引用:2017届河北省曲周县第一中学高三下学期第一次模拟考试文数试卷
14-15高二上·河北邯郸·期末
7 . 已知等差数列
中满足
,
.
(1)求
和公差
;
(2)求数列
的前10项的和.
![](https://img.xkw.com/dksih/QBM/2014/3/7/1571549566066688/1571549571817472/STEM/a3c288a73fcf4792af799e2c2ab491fe.png)
![](https://img.xkw.com/dksih/QBM/2014/3/7/1571549566066688/1571549571817472/STEM/289e824b3a7a49dda60a6b43c7a74a27.png)
![](https://img.xkw.com/dksih/QBM/2014/3/7/1571549566066688/1571549571817472/STEM/6dabbd61ae68495ea025563f4bd8bade.png)
(1)求
![](https://img.xkw.com/dksih/QBM/2014/3/7/1571549566066688/1571549571817472/STEM/dc5accb935a641f18d376c1f8fa80666.png)
![](https://img.xkw.com/dksih/QBM/2014/3/7/1571549566066688/1571549571817472/STEM/3fcc4bc7a2774077bd7bbadaae054625.png)
(2)求数列
![](https://img.xkw.com/dksih/QBM/2014/3/7/1571549566066688/1571549571817472/STEM/a3c288a73fcf4792af799e2c2ab491fe.png)
您最近一年使用:0次
2011·福建莆田·一模
名校
8 . 在递减等差数列
中,若
,则
取最大值时
等于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57064709907bf982ae6bd9e6076240a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
A.2 | B.3 | C.4 | D.2或3 |
您最近一年使用:0次
2017-06-03更新
|
442次组卷
|
3卷引用:河北省临漳县第一中学2017-2018学年高二上学期第一次月考数学试题(艺术普通班)
河北省临漳县第一中学2017-2018学年高二上学期第一次月考数学试题(艺术普通班)(已下线)2011届福建省莆田市高中高三毕业班适应性练习理科数学河北省枣强中学2016-2017学年高二下学期第三次月考数学(文)试题
名校
解题方法
9 . 已知
是首项为
,公差为
的等差数列,
是其前
项的和,且
.
(1)求数列
的通项
及
;
(2)设
是首项为1,公比为3的等比数列.求数列
的通项公式及其前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c02bc0c74292b1e8f395f90935d3174.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b8877e5142f999d939b3db17f749a7f.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7783af5ca752a86c0970358c692c9f18.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)
您最近一年使用:0次
2016-12-04更新
|
437次组卷
|
3卷引用:2015-2016学年河北省成安一中、永年二中高二上期中文科数学试卷
名校
10 . 设等差数列
前
项和为
,且满足
;等比数列
满足
.求数列
的通项公式;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe229b24e2d56ff6b491725ceae4ff2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b708c8dcb2d66eb2ce0b3718a9cd924a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6fd29739f5e14f6a7565c9a228f93250.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bee4464b3b4eb6e52ee02f095aae84f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae9a9d04e9c822595f6ffc779fef6f4a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c374a7d77deec9323982e0c26b4a2e85.png)
您最近一年使用:0次