1 . 已知等差数列
的前n项和为
,
,
.
(1)求
的通项公式;
(2)求
,并求当n取何值时
有最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b28ef6f1b2279af482557a8ea46f2e43.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/822f00db0798ae2d559eb55670e07703.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/416e9cc3d123571da05db298e01e1bf6.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b28ef6f1b2279af482557a8ea46f2e43.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
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2022-10-20更新
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16卷引用:青海省西宁市2021-2022学年高一下学期期末数学试题
青海省西宁市2021-2022学年高一下学期期末数学试题青海省西宁北外附属新华联外国语高级中学2022-2023学年高二上学期第一次月考数学试题宁夏银川市银川一中2019-2020学年高三上学期第二次月考数学(文)试题黑龙江省大庆中学2019-2020学年高一4月网上考试数学试题陕西省榆林市绥德中学2020届高三下学期第六次模拟考试数学(文)试题(已下线)第02章数列(A卷基础篇)-2020-2021学年高二数学必修五同步单元AB卷(人教A版,浙江专用)贵州省贵阳市民族中学2020-2021学年高一下学期第一次月考数学试题重庆市凤鸣山中学2022届高三上学期期中数学试题河南省平顶山市郏县第一高级中学2021-2022学年高二下学期开学收心考试数学(理)试题(已下线)专题4.1 等差数列的性质-2021-2022学年高二数学特色专题卷(人教A版2019选择性必修第二册)四川省攀枝花市第七高级中学校2021-2022学年高一下学期第一次月考数学(理)试题上海奉贤区致远高级中学2022-2023学年高二上学期期中数学试题(已下线)第四章 数列 讲核心 01(已下线)4.2.3 等差数列的前n项和-2022-2023学年高二数学《基础·重点·难点 》全面题型高分突破(苏教版2019选择性必修第一册)(已下线)高二下期中真题精选(常考60题专练)-【满分全攻略】2022-2023学年高二数学下学期核心考点+重难点讲练与测试(沪教版2020选修一+选修二)(已下线)期中真题必刷常考60题(22个考点专练)-【满分全攻略】2023-2024学年高二数学同步讲义全优学案(沪教版2020必修第三册)
名校
2 . 已知等差数列
的公差
,前
项和为
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/812be9806122241c476ba1db516c4823.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a78dc7c7fcca8c1bbe31290ccbbf4c87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a2112cfe33ca0bbe328416b838e453f.png)
A.6 | B.![]() | C.![]() | D.8 |
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7卷引用:青海省海东市民和回族土族自治县城西高级中学2023-2024学年高二下学期3月月考数学试题
青海省海东市民和回族土族自治县城西高级中学2023-2024学年高二下学期3月月考数学试题河北省武安市第三中学2021-2022学年高二上学期第二次月考数学试题(已下线)第04讲 复习课-数列-【寒假自学课】2022年高二数学寒假精品课(苏教版2019选择性必修第二册)辽宁省辽西联合校2021-2022学年高二下学期期中考试数学试题广西钦州市第十三中学2022-2023学年高二下学期期中考试数学试题河北省深州市中学2023-2024学年高三上学期期中考试数学试题陕西省西安市西光中学2023-2024学年高二上学期期末考试数学试题
3 . 北京天坛的圜丘坛为古代祭天的场所,分上、中、下三层,上层中心有一块圆形石板(称为天心石),环绕天心石砌9块扇面形石板构成第一环,向外每环依次增加9块,下一层的第一环比上一层的最后一环多9块,向外每环依次也增加9块,已知每层环数相同,均为9环,则三层共有扇面形石板(不含天心石)数量是___________ .
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/14/a256ac12-44c4-4739-a1f5-8c71f35d0a37.png?resizew=151)
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4卷引用:青海省西宁市海湖中学2022-2023学年高二下学期开学摸底考试数学试卷 A卷
名校
4 . 等差数列
中,
,
,设
是数列
的前n项和,则
=___________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcabb62c63cce7e3fa9f6203ecc5aeab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25131d323ad4304473cbd09ac0c1bb02.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/7eed39c7d611309b01476c15ab242308.png)
您最近一年使用:0次
名校
5 . 已知等差数列
和
的前
项和分别为
和
,若
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/338ca4f96c949e715e0c7788b14b79ad.png)
______ .
![](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/ed1b621cb77dd03d408e76df1663038c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/338ca4f96c949e715e0c7788b14b79ad.png)
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6卷引用:青海省海南州高级中学2021-2022学年高三上学期摸底考试理科数学试题
6 . 已知等差数列
的前
项和为
,且
,
.
(1)求数列
的通项公式;
(2)记
,数列
的前
项和为
,证明:
.
![](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/210f3edc97bd476d16735c11940d777f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b3e73636607382b8a2c4af65cd6def7.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d81dd89ecc74786f2701653dbe27781b.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)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6828a1cf75f19bb74a0e0490bd65c168.png)
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|
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|
2卷引用:青海省西宁市城西区青海湟川中学2020-2021学年高二上学期期中数学试题
解题方法
7 . 设
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.
(1)求数列
的通项公式;
(2)令
,
,2,…,求数列
的前
项和
.
![](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/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ccdc17b603871d20843ffccca2df0ae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7131900393b9906bd6dcfe26ade2059f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/911278aa8595846abac1972e1de59995.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0462c9dc4a0bd08a0ec1cc07f1d2f3e6.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/010baf415f792018ad9abd752e37b983.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c87b351f16728b0023fd63678f8103c7.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
8 . 已知等差数列
的前
项和为
,公差为3,若
,
,
成等比数列,则
( )
![](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/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6555ad7e12c040eee6a2f9beb812742d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5da4cd81500bdb43118150dbdb1541e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/614306cc3f34bdee4d5d885b79667645.png)
A.9或13 | B.13 |
C.15或35 | D.35 |
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|
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7卷引用:青海省玉树藏族自治州第二民族高级中学2022-2023学年高二上学期期末考试数学试题
名校
9 . 已知数列
为等差数列,
为数列
的前
项和,
,则
等于( )
![](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/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ecd50a615f51e3a73e2fddf58125915f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/194592cb77de8a597d5d64e1c85c3249.png)
A.5 | B.15 | C.30 | D.35 |
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|
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7卷引用:青海省海东市第二中学2020-2021学年高一下学期期中数学试题
青海省海东市第二中学2020-2021学年高一下学期期中数学试题广西河池市2020-2021学年高二上学期期末数学(文)试题广西河池市2020-2021学年高二上学期期末数学(理)试题广西来宾市2020-2021学年高二上学期期末数学(文)试题广西来宾市2020-2021学年高二上学期期末数学(理)试题(已下线)突破4.2.2 等差数列的前n项和课时训练-【新教材优创】突破满分数学之2020-2021学年高二数学课时训练(人教A版2019选择性必修第二册) 河南省顶尖名校联盟2021-2022学年高二上学期期中联考理科数学试题
名校
解题方法
10 . 已知
是等差数列,
,
.
(1)求
的通项公式;
(2)求数列
的前n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/ff1b8d0eddf9a3442463159dd26b6d23.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61e2b1f93b10af8ee020c288c914f712.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
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