14-15高三上·辽宁·期中
名校
1 . 设数列{an}是公差d<0的等差数列,Sn为其前n项和,若S6=5a1+10d,则Sn取最大值时,n的值为
A.5 | B.6 | C.5或6 | D.11 |
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13-14高一下·辽宁沈阳·期中
名校
2 . 等差数列{
}前n项和为
,满足
,则下列结论中正确的是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2feec56fa736d7c1c454d31e49ca18e2.png)
A.![]() ![]() | B.![]() ![]() |
C.![]() | D.![]() |
您最近一年使用:0次
2016-12-03更新
|
874次组卷
|
5卷引用:2013-2014学年辽宁省沈阳东北育才双语学校高一下学期期中数学卷
(已下线)2013-2014学年辽宁省沈阳东北育才双语学校高一下学期期中数学卷2015-2016学年吉林省吉林一中高二下开学验收数学试卷陕西省商洛市洛南中学2020-2021学年高二上学期第一次月考数学试题江苏省连云港市海头高级中学2020-2021学年高二上学期第二次月考数学试题(已下线)第02讲 等差数列及前n项和(讲)
13-14高二下·北京西城·期末
解题方法
3 . 已知数列{an}是公差为﹣2的等差数列,a6是a1+2与a3的等比中项.
(1)求数列{an}的通项公式;
(2)设数列{an}的前n项和为Sn,求Sn的最大值.
(1)求数列{an}的通项公式;
(2)设数列{an}的前n项和为Sn,求Sn的最大值.
您最近一年使用:0次
4 . 等差数列
前
项和为
,已知
为________ 时,
最大.
![](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/9bbe8eb70df862dee4ae15bcdcc05681.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
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2016-12-03更新
|
1110次组卷
|
2卷引用:安徽省池州市江南中学2016-2017学年高一下学期期末考试数学试题
13-14高一下·江苏扬州·期中
5 . 设等差数列{an}的前n项的和为Sn,若a1>0,S4=S8,则当Sn取最大值时,n的值为____________ .
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13-14高三上·陕西·阶段练习
6 . 已知等差数列
中,
为其前
项和,若
,
,则当
取到最小值时
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/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1549723d901eeb2cf966e322f404a5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6cc1ec50ff0c75ebb3d136144ddc8d23.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
A.5 | B.7 | C.8 | D.7或8 |
您最近一年使用:0次
名校
7 . 已知等差数列
的公差
,前
项和
满足:
,那么数列
中最大的值是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f2a482b048ada7bc981a416116fa2b6.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/82c262d39a553626aaa3e4ec221f76c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0519af3f19dde038fab2e68b5e2a5387.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
2016-12-02更新
|
730次组卷
|
2卷引用:吉林省吉林市长春汽车经济开发区第六中学2016-2017学年高一下学期期末考试文数试题
12-13高一·浙江宁波·期中
名校
8 . 在等差数列
中,
,则数列
前
项和
取最大值时,
的值等于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d737c1047a14cee12a6671383e244fa5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8648b3cf94be23d001f0e39fd905fba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d737c1047a14cee12a6671383e244fa5.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)
A.12 | B.11 | C.10 | D.9 |
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13-14高二上·河南三门峡·阶段练习
9 . 已知数列的通项公式
,则
取最小值时
=_______________ ,
此时
=_________ .
![](https://img.xkw.com/dksih/QBM/2013/3/26/1571162834935808/1571162840563712/STEM/745d447e0a6f47cda3fe683c531ca7ac.png?resizew=85)
![](https://img.xkw.com/dksih/QBM/2013/3/26/1571162834935808/1571162840563712/STEM/879d5ab05c6140fe9011a34c44ab8801.png?resizew=20)
![](https://img.xkw.com/dksih/QBM/2013/3/26/1571162834935808/1571162840563712/STEM/0732dd1be6ad4d89b3293b9f4faec640.png?resizew=13)
此时
![](https://img.xkw.com/dksih/QBM/2013/3/26/1571162834935808/1571162840563712/STEM/879d5ab05c6140fe9011a34c44ab8801.png?resizew=20)
您最近一年使用:0次
13-14高三上·辽宁朝阳·阶段练习
解题方法
10 . 等差数列
,该数列前n项和
取最小值时,n=_______ .
![](https://img.xkw.com/dksih/QBM/2013/7/1/1571262799323136/1571262804647936/STEM/2ff0e6203ccb49a7b82762c57eb7aa8a.png?resizew=148)
![](https://img.xkw.com/dksih/QBM/2013/7/1/1571262799323136/1571262804647936/STEM/811ba64e4f994e7790f2fd70af2b2f46.png?resizew=20)
您最近一年使用:0次