11-12高三上·浙江杭州·阶段练习
1 . 已知等差数列
满足
,若
,则
的最大值为__________
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a22589eaf617389833827ee3aebbdcf6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
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10-11高二上·福建福州·期中
名校
2 . 在等差数列{
}中,
=18,前5项的和![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bccd6b7cf0721f738ea046cd6399ca7.png)
(1)求数列{
}的通项公式; (2)求数列{
}的前
项和的最小值,并指出何时最小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e35eeaabd951fb09b2926807da3685b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bccd6b7cf0721f738ea046cd6399ca7.png)
(1)求数列{
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://img.xkw.com/dksih/QBM/2010/11/26/1569918639202304/1569918644436992/STEM/3fbb28ca241348ac88a69e65b4b08403.png?resizew=13)
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2016-11-30更新
|
877次组卷
|
4卷引用:2010年福建省福州市高级中学高二上学期期中考试数学理卷
(已下线)2010年福建省福州市高级中学高二上学期期中考试数学理卷广东省广东实验中学2019-2020学年高二上学期开学摸底考试数学试题北京科技大学附属中学2020-2021学年高二上学期期末考试数学试题黑龙江省哈尔滨市宾县第二中学2021-2022学年高二上学期期末数学试题
9-10高一下·广东湛江·期末
3 . 设等差数列
第10项为24,第25项为-21,.
(1)求这个数列的通项公式;
(2)设
为其前
项和,求使
取最大值时的
值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(1)求这个数列的通项公式;
(2)设
![](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/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
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9-10高二下·广东广州·期中
解题方法
4 . 设等差数列
的前
项和为
且满足
则
中最大的项为______.
![](https://img.xkw.com/dksih/QBM/2014/5/12/1571704129732608/1571704135090176/STEM/db5ecf28b15a4ead83c13beb68e6dffa.png?resizew=32)
![](https://img.xkw.com/dksih/QBM/2014/5/12/1571704129732608/1571704135090176/STEM/8d51e44cbedc489fa2e86014c19a07a0.png?resizew=13)
![](https://img.xkw.com/dksih/QBM/2014/5/12/1571704129732608/1571704135090176/STEM/c38e12a576374d299f2bfc6bcfb71741.png?resizew=25)
![](https://img.xkw.com/dksih/QBM/2014/5/12/1571704129732608/1571704135090176/STEM/cf79ec6fe2a346cea65b8fa8a1cce530.png?resizew=104)
![](https://img.xkw.com/dksih/QBM/2014/5/12/1571704129732608/1571704135090176/STEM/c9cb80573ddb442eb5a4a77842fef174.png?resizew=91)
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9-10高一下·浙江宁波·期中
5 . 若无穷等差数列
的前
项和为
,且
,
,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/6df775bbb96051716b1971fdfc42c210.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5ad422a03467f70121b4a3cd3c724d9.png)
A.在![]() |
B.![]() |
C.![]() |
D.![]() |
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2010·上海长宁·二模
名校
6 . 在等差数列{an}中,满足3a4=7a7,且a1>0,Sn是数列{an}前n项的和,若Sn取得最大值,则n=_________ .
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