1 . 已知等差数列
的前
项和为
,且
,
.
(1)求数列
的通项公式;
(2)记
,数列
的前
项和为
,证明:
.
![](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/210f3edc97bd476d16735c11940d777f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b3e73636607382b8a2c4af65cd6def7.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d81dd89ecc74786f2701653dbe27781b.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)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6828a1cf75f19bb74a0e0490bd65c168.png)
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2021-09-08更新
|
352次组卷
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2卷引用:青海省西宁市城西区青海湟川中学2020-2021学年高二上学期期中数学试题
名校
解题方法
2 . 在等差数列
中,
,
.
(1)求数列
的通项公式;
(2)设数列
是首项为1,公比为2的等比数列,求
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d82583380f57b1285521011a911c7d73.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/953446978166449bc5c73cd993d10af7.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)设数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5344eadd4711db34e3f935aedd5fb270.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/08eb71ecf8d733b6932f4680874dbbf3.png)
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2020-03-27更新
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6卷引用:青海省大通回族土族自治县第一完全中学2019-2020学年高一下学期期中联考数学试题
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3 . 在等差数列
中,
表示
的前
项和,若
,则
的值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe229b24e2d56ff6b491725ceae4ff2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b708c8dcb2d66eb2ce0b3718a9cd924a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe229b24e2d56ff6b491725ceae4ff2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3f1afed775b6b228196e2e21f26574e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d3a072c2baa062dfd3d5e5a267fe227.png)
A.![]() ![]() | B.![]() ![]() | C.![]() ![]() | D.![]() |
您最近一年使用:0次
2018-11-23更新
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742次组卷
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5卷引用:青海省西宁市第十四中学2019-2020学年高二上学期期中数学(理)试题
名校
4 . 设等差数列
,
的前
项和分别为
,
,若
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8aa3236498f80bc9e0eb439736099353.png)
__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fce83115a50f99e08e9a2db7267aeed.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/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4366a23c95de8f2ceca6f337130d8b99.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8aa3236498f80bc9e0eb439736099353.png)
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2018-05-30更新
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9卷引用:青海省海南州高级中学、贵德中学2020-2021学年高一下学期期中联考数学试题
青海省海南州高级中学、贵德中学2020-2021学年高一下学期期中联考数学试题【全国省级联考】湖北省2017-2018学年高二下学期期末阶段摸底调研联合考试数学(理)试题【全国百强校】安徽省太和中学2018-2019学年高一下学期第三次月考数学(理)试题【全国百强校】安徽省太和中学2018-2019学年高一下学期第三次月考数学(文)试题河北省深州中学2018-2019学年高一下学期期末考试数学试题【全国百强校】河北省深州市中学2018-2019学年高一下学期期末考试数学试题安徽省六安市第一中学2019-2020学年高二上学期开学考试数学(理)试题湖北省十堰市2017-2018学年高一下学期期末数学(理)试题湖北省十堰市2017-2018学年高一下学期期末数学(文)试题
名校
解题方法
5 . 已知等差数列
的前
项和为
,且满足
.
(1)求数列
的通项公式;
(2)若
,求数列
的前
项和
.
![](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/11182e213c13205809a3b2385d069787.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95e191086446263b7bbbd93613577c42.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)
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2017-06-28更新
|
870次组卷
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7卷引用:青海省海东市第二中学2019-2020学年高一下学期期中考试数学试题