1 . 设等差数列
的前
项和为
,
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc4e70b360f988fdbd92300ab22c4613.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/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39f0a04d3f3224d9d7cab3c93830ccbb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc4e70b360f988fdbd92300ab22c4613.png)
您最近一年使用:0次
名校
解题方法
2 . 设
是公比为负数的等比数列,
为
,
的等差中项,
.
(1)求数列
的通项公式;
(2)设
,求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7755b0ec8df40da1e10c3567e441be7f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c1ccc6c74b8754e9bcbb3f39a11b6f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/874e1398a3cdc4dfb36bf2a956b07463.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3b02b2d25602b385a0cec79e94aa6e3.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
2021-11-21更新
|
642次组卷
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7卷引用:辽宁省沈阳市市级重点高中联合体2021-2022学年高二下学期期中考试数学测试题
名校
3 . 设等差数列{an}的前n项和为Sn,若S6=12,则a3+a4=( )
A.3 | B.4 | C.6 | D.7 |
您最近一年使用:0次
2019-12-02更新
|
275次组卷
|
2卷引用:辽宁省沈阳市城郊市重点联合体2019-2020学年高二上学期期中数学(理)试题
名校
4 . 在各项均为正数的等比数列
中,
,且
,
,
成等差数列.
(1)求数列
的通项公式;
(2)若数列
满足
,
为数列
的前
项和. 设
,当
最大时,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f966272f7781790ff27e40db6b525253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e86e2e42b4aa93db9241103e7f61766c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f65fc200f10b97588a0c9896277c9c64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/549980ea98031b87af7a207b879d5ba1.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82d524341a7b48aacd9e695d6dc400b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.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/8cee7e74da50a77e3655c068a2a10cb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c59e7c7a84a4bdb959e95536d0404ceb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
您最近一年使用:0次
2018-11-19更新
|
586次组卷
|
2卷引用:【全国百强校】辽宁省沈阳市东北育才学校2018-2019学年高二上学期期中考试数学试题
10-11高三·重庆·阶段练习
名校
解题方法
5 . 已知实数a,
,a,b的等差中项为
,设
,则
的最小值为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/987517758fad59f6f695761deb2a5ebd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d19bce4c604450307f40dcbd6a9ca6c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8eff998d034284391ca064755fa6bf1b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72806f7827ed443408e2395fe8c6e57e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6524a42af893ca35c6b92c4e82d0058.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11d71379442f28c038d367d49422cf90.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/987517758fad59f6f695761deb2a5ebd.png)
A.3 | B.4 | C.5 | D.6 |
您最近一年使用:0次
2016-12-03更新
|
970次组卷
|
8卷引用:2014-2015学年辽宁省沈阳二中高二下学期期中考试理科数学试卷