名校
解题方法
1 . 已知等差数列
的前
项和为
,
,
,则
的值为( )
![](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/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/afbfd6b761451716ba3d7130c93497ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f3cf6f2bbe20a404fea41a4d2b1c4c7.png)
A.70 | B.80 | C.90 | D.100 |
您最近一年使用:0次
名校
解题方法
2 . 设数列
满足:①
;②所有项
;
③
.设集合
,将集合
中的元素的最小值记为
.换句话说,
是数列
中满足不等式
的所有项的项数的最小值.我们称数列
为数列
的伴随数列.例如,数列1,3,5的伴随数列为1,2,2,3,3.
(1)请写出数列1,5,7的伴随数列;
(2)设
,求数列
的伴随数列
的前30项之和;
(3)若数列
的前
项和
(其中
常数),求数列
的伴随数列
的前
项和
.
![](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/9b614e06663d93a618d95f416e35af54.png)
③
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dd992f0b72c282959031890e58c7810.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a1290895db96907d5054c7cc8ab2f06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a0d7559d8dfa8236ca9d4b1853fbdec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f64696f60c533ad95dc7890eb902741.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f64696f60c533ad95dc7890eb902741.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63cad0f23354aa754ade482d849557fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(1)请写出数列1,5,7的伴随数列;
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbb2f1272b626e0fd5c79c1a91d48b07.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(3)若数列
![](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/7051ba2351ffb1a1900f931833054bac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62c320a0619c63a5b650a1a94c0a5679.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7e74be91bfe4bc209da7539dbf9b72c.png)
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3 . 将正方形
分割成
个全等的小正方形(图1、图2分别给出了
的情形),在每个正方形的顶点各放置一个数,使位于正方形
的四边及平行于某边的任一直线上的数都分别依次成等差数列.若顶点
处的四个数互不相同且和为1,记所有顶点上的数和为
,则有
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/022205c82846dfa3420c67402a278fea.png)
______ ,…,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d64205bb7d470602fb525b02e72a81b.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/188ba12941ea122a7775a4999e129161.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d15d4afcc5736bb747eeffcffd3f4464.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c82a10b4f0c9323d726804c89dd9548.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e345e86daf74312a6992e5d1c3f47f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cf8c7f5f6a35f7ed88271a077619aef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/022205c82846dfa3420c67402a278fea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d64205bb7d470602fb525b02e72a81b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/5/29/8a0dc8d3-051d-4666-9a45-8e1c699ed7bd.png?resizew=254)
您最近一年使用:0次
4 . 已知集合
,
,
,集合
,将集合D中所有元素从小到大依次排列为数列
,
为数列
的前n项和.集合
,将集合E的所有元素从小到大依次排列为数列
.则( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d51fbdfa0ffc3b23ba28d150c4ca97fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4f7a7124e05bdf628bca3fd0e21914c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fb13d3a1a38c1a5bcd6b33bec963f75.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daaf64d8a4a57ddd03c2718d775fc34c.png)
![](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/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55fa10a8b27c1b17d5b00b91d8cdbee3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
A.![]() |
B.![]() |
C.![]() |
D.若存在![]() ![]() |
您最近一年使用:0次
名校
5 . 设
是等差数列
的前n项和,且
,则下列结论正确的是( )
![](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/2f0fb2f484d3d73b26acc02ffdc56a3d.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
6 . 数列
,
为其前
项和,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb261bb45b5137a7236ccddcfdface6f.png)
__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b05d95890aaaa830d1991a9c8749990a.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/eb261bb45b5137a7236ccddcfdface6f.png)
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名校
7 . 等差数列
的前n项和为
,若
,
,则
( )
![](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/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced4e381e8c3336848b8c436dbc584f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9620357ea5be4037cfdccd09a27d3862.png)
A.12 | B.10 | C.8 | D.6 |
您最近一年使用:0次
名校
8 . 已知等差数列
的前
项和为
,则
( )
![](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/24466c9f50166bb4be99caee103d77f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/554e6c461ccc5aa3093c524aa528a4e2.png)
A.14 | B.26 | C.28 | D.32 |
您最近一年使用:0次
2024-05-08更新
|
427次组卷
|
2卷引用:辽宁省本溪市县级重点高中协作体2023-2024学年高二下学期期中考试数学试卷
名校
解题方法
9 . 记等差数列
的前n项和为
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fb6220c0860951f19a3de272d4cdd69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3adf2bf9a573b812ba2039e75368395.png)
A.98 | B.112 | C.126 | D.140 |
您最近一年使用:0次
2024-04-06更新
|
341次组卷
|
2卷引用:辽宁省沈阳市五校协作体2023-2024学年高二下学期期中考试数学试卷
名校
解题方法
10 . 已知
为等差数列,前
项和为
,且
,
,则
( )
![](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/039e4fe671d61e59b96ee525c9df43e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/696865ee1296987cc23d294d9b3efeaf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42e4487468ab2823d6dbf7f0ebd2eb38.png)
A.54 | B.45 | C.23 | D.18 |
您最近一年使用:0次
2024-03-27更新
|
888次组卷
|
2卷引用:辽宁省朝阳市建平县实验中学2023-2024学年高二下学期5月期中考试数学试题