解题方法
1 . 已知等差数列
的前
项和为
,若
,且
,则
的最小值为_________ .
![](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/4ac577f987d768e1a115f2747ec0fd6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c20b3db49566d59fa4160f2ddf26815.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
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11-12高一下·四川攀枝花·阶段练习
解题方法
2 . 等差数列
中,
,
,且
,
是前
项和,则下列判断正确的有_______ .
①数列
的最小项是
;
②
,
,
;
③
先单调递减后单调递增;
④当
时,
最小;
⑤
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88b8be47f727e800bef9b647254dd432.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b499db552a74e4d609391271dcf72ad2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de0db09c9753bb386bdf8fd9c7ae6dec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
①数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
②
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/486cddc710aec81c76b5b395446eaa00.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ad3bdc2cf20eefdf5b999239cc6f935.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce868ac245a30cc99db2b35b2fabc545.png)
③
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
④当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c345907ebe27888332b1b44c666cc47.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
⑤
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb6ebaeb63ef37c1d92f44777ac97b58.png)
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11-12高一下·四川雅安·阶段练习
名校
3 . 数列
是首项为23,公差为整数的等差数列,且前6项为正,从第7项开始变为负
(1)求此等差数列的公差d;
(2)设前n项和为
,求
的最大值;
(3)当
是正数时,求n的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(1)求此等差数列的公差d;
(2)设前n项和为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(3)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
您最近一年使用:0次
2016-12-01更新
|
840次组卷
|
3卷引用:2011-2012学年四川省雅安中学高一下学期3月月考理科数学试卷
(已下线)2011-2012学年四川省雅安中学高一下学期3月月考理科数学试卷2014-2015学年四川省德阳市五中高一下学期期中考试数学试卷四川省雅安中学2018-2019学年高一下学期期中考试数学试题
10-11高一下·内蒙古赤峰·期中
名校
4 . 已知等差数列{an}的前n项的和记为Sn.如果
,
.
(1)求数列{an}的通项公式;
(2)求Sn的最小值及其相应的n的值;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4856b98baa33a79c4c9816eba36fb844.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a442209925cb703cf0185c3bd8e0197b.png)
(1)求数列{an}的通项公式;
(2)求Sn的最小值及其相应的n的值;
您最近一年使用:0次
2016-11-30更新
|
973次组卷
|
4卷引用:四川省眉山市东坡区多悦高级中学校2019-2020学年高一下学期期中考试数学试题
四川省眉山市东坡区多悦高级中学校2019-2020学年高一下学期期中考试数学试题(已下线)2010-2011年内蒙古赤峰二中高一第二学期期中考试(音体美类)数学河北省唐山市滦南县第二高级中学2019-2020学年高一下学期期末数学试题河北省石家庄市第二中学2020-2021学年高二上学期8月线上考试(二)数学试题
10-11高二下·四川雅安·期中
名校
5 .
是等差数列
的前n项和,若
,则当
时,
取最大值.
![](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/8f7d13d855ea786a60db8c2b6f61e7fb.png)
![](https://img.xkw.com/dksih/QBM/2011/4/22/1570126179434496/1570126184644608/STEM/7d5a9b166188424583f31ffb0a1b0434.png?resizew=55)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
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