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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16卷引用: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
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(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)
解题方法
2 . 数列{an}中,如果an=49﹣2n,则Sn取最大值时,n等于( )
A.23 | B.24 | C.25 | D.26 |
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解题方法
3 . 已知等差数列
的前
项和为
,若
,
,则使得
取最小值的
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/179513ce80436471efbe1d9b31735f7d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b996470ff3567eafc43231210c1c7c8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
A.11 | B.12或13 | C.12 | D.13或14 |
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3卷引用:河南省安阳市2021-2022学年高二下学期5月月考数学文科试题
4 . 已知数列
满足
,设
.
(1)证明:数列
为等差数列,并求
的通项公式;
(2)求数列
的前
项和
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/150621da3f2afebfd4dd8df7fa7e507e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14f989f6932c4ecdea167da06b89ffd5.png)
(1)证明:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)求数列
![](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)
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5 . 数列
的前
项和为
,已知
,则下列说法错误的是( )
![](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/98330ed390da74f2ebbe52d1c4af3183.png)
A.![]() |
B.![]() |
C.当![]() ![]() |
D.当![]() ![]() ![]() |
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|
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4卷引用:河南省信阳市商城县观庙高级中学2021-2022学年高二上学期12月月考数学(文)试题
名校
解题方法
6 . 已知等差数列
的公差
,若
,
,则该数列的前
项和
的最大值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2d8bbb4a09e0ac86bbae46222a90841.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58411513922ca0bcfa189c3f2787f336.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a612f917f74b81a0700bd8976e6094cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
A.30 | B.35 | C.40 | D.45 |
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4卷引用:河南省中原名校2021-2022学年高二上学期期末联考文科数学试题
7 . 设
为等差数列
的前
项和,且
,
,则
的取值范围是( )
![](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/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7139d20025d82f1595e2207aebe9be56.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e3931e6266decbab4ab76b280f61bda.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/194592cb77de8a597d5d64e1c85c3249.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
8 . 设等差数列
的前n项和为
,若
,
,则当
取最大值时,n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/366dfedff1a1a96ec27650375b680059.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/572645ce9a4daec17e5915d9efac96d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
A.4 | B.5 | C.6 | D.7 |
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|
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2卷引用:河南省洛阳市2021-2022学年高二上学期期中考试数学(文)试题
9 . 在等差数列
中,已知
,
.
(1)求
的通项公式;
(2)若
的前
项和为
,求
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f3af4204cbd59c0bc15f5d83b240a7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32f617b2a3d26346cdae3c01a545089c.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若
![](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/08eb71ecf8d733b6932f4680874dbbf3.png)
您最近一年使用:0次
10 . 已知等差数列
的前
项和
有最小值,且
,则使得
成立的
的最小值是___________ .
![](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/29cde5f8515bed66e762e4a6489a0527.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49763402b2f2023f0ba64c37924267d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
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