1 . 各项均为正数的等差数列
的前n项和是
,若
,则
的值为_________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0280a149cb19a9781d9bcb6187191e4a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba48780e63a87aaf7f1d7fa29dd56b5c.png)
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解题方法
2 . 已知数列
为等比数列,且
是
与
的等差中项,若
,则该数列的前5项和为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c1ccc6c74b8754e9bcbb3f39a11b6f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ebfa14def8b0176f9f0bcb6d9ceeaa4b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/039e4fe671d61e59b96ee525c9df43e8.png)
A.2 | B.10 | C.31 | D.62 |
您最近一年使用:0次
2023-02-13更新
|
503次组卷
|
4卷引用:山东省济宁市2022-2023学年高二上学期期末数学试题
3 . 设
是等差数列
的前
项和,若
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/883329a08800ca11b52b0ff16ded14af.png)
______ .
![](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/81f667ea9d53ac41218ac830b8011ee8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/883329a08800ca11b52b0ff16ded14af.png)
您最近一年使用:0次
2023-02-13更新
|
618次组卷
|
2卷引用:上海市复旦大学附属中学2022-2023学年高二上学期期末数学试题
4 . 等比数列
中,
,且
成等差数列.
(1)求数列
的通项公式;
(2)若数列
,求数列
前
项的和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/039e4fe671d61e59b96ee525c9df43e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4ff44ba6a877e955fde6b3c0c029a02.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/194d903d10f1568ae87832407f22cc29.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
5 . 将
这九个数填入如图所示的
正方形网格中,每个小方格中只能填一个数,每个数限填一次.考虑网格中每行从左到右、每列从上到下、两条对角线从上到下所填的数各构成一个数列,共计八个数列,则下列结论中正确的有( )
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/12/f38903a1-4143-409d-b832-3302b970bf28.png?resizew=86)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb8f3184e51b3556641a1cb261292796.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/777d8fccf0cf8b55a68488fe48b78744.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/12/f38903a1-4143-409d-b832-3302b970bf28.png?resizew=86)
A.这八个数列有可能均为等差数列 |
B.这八个数列中最多有三个等比数列 |
C.若中间一行、中间一列、两条对角线上的数列均为等差数列,则中心小方格中所填的数必为5 |
D.若第一行、第一列上的数列均为等比数列,则其余数列中至多有一个等差数列 |
您最近一年使用:0次
6 . 设两个等差数列
,
的前
项和分别为
、
,已知
,求
的值.
![](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/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de3a95f5e1042a10960d7774bdd00674.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/265397c51288caa8df9b42f1f698b5a5.png)
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7 . 在
和
之间插入两个数,使前三个数成等比,后三个数成等差,求插入的这两个数.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b53c7539ed297ea63b9ace6f5cc58ca8.png)
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8 . 等差数列
中,
,
,则数列的公差![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c98c59cd4749afdd21e73529fc84323.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/036e142e3ee7263db59c072d386598a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95d1f8178428f9fc9bdbe08479b76a65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c98c59cd4749afdd21e73529fc84323.png)
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9 . 已知
,成等差数列,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ec0618ae3a4fde6d6220010af229b9a.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/942c0fe4561f73a15cffd1f4bfda8690.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ec0618ae3a4fde6d6220010af229b9a.png)
您最近一年使用:0次
2023-02-07更新
|
316次组卷
|
2卷引用:沪教版(2020) 选修第一册 高效课堂 第四章 4.1 等差数列(2)
解题方法
10 . 函数
,等差数列
公差为
,若
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ddd1477960b276ccc98b994cfc9565b.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99eaeb2ab68a49074d623ffca072fed8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/483fcea7bf028fbd5608157a581c7102.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ddd1477960b276ccc98b994cfc9565b.png)
您最近一年使用:0次