1 . 若数列
的通项
,由
,
所确定的数列
的前n项和为______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a5c1428b4c14e43905f0f0f49df6d8e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a30a69a23259d9a8e7ac6b0c5d899428.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db7a7dfca6af63b476b343e67eb3201f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
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2 . 已知等比数列
中,
,
,
,数列
的前
项和为
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56806b4d9207fb691270e0fb981c787b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2693734765399876e9e93cdb110231c4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04a937bfa81842d63375e8976f7aa889.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b83de9a45d9b680da8835bac1fee9c9b.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/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56806b4d9207fb691270e0fb981c787b.png)
A.36 | B.28 | C.45 | D.32 |
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2018-06-11更新
|
4746次组卷
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3卷引用:甘肃省张掖市山丹县第一中学2019-2020学年高二上学期期中考试数学(文)试题
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3 . 我国古代数学著作《九章算术》有如下问题:“今有金箠,长五尺,斩本一尺,重四斤,斩末一尺,重二斤,问次一尺各重几何?”意思是:“现有一根金箠,长5尺,一头粗,一头细,在粗的一端截下1尺,重4斤;在细的一端截下1尺,重2斤;问依次每一尺各重多少斤?”设该金箠由粗到细是均匀变化的,则金箠的重量为
A.15斤 | B.14斤 | C.13斤 | D.12斤 |
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2018-03-30更新
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4卷引用:甘肃省张掖市2018届全市高三备考质量检测第三次诊断考试数学(理)试题
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4 . 已知数列
的通项公式为
.
(1)求证:数列
是等差数列;
(2) 令
,求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a19f2d06f660b6bdadb83c0c6c62310.png)
(1)求证:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
(2) 令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e4e834a9a9288f5bf8356eb691ca36f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fce83115a50f99e08e9a2db7267aeed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d07ae0b4264da6a8812454ffd2f20d94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f3cf6f2bbe20a404fea41a4d2b1c4c7.png)
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2018-03-11更新
|
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3卷引用:甘肃省张掖市民乐县第一中学2018-2019学年高二上学期期中数学试题
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5 . 设等差数列
的前
项和为
,且满足
,
.
(
)求
的通项公式.
(
)求
的前
项和
及使得
取到最大值时
的值并求出
的最大值.
![](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/4ac8419cf6c0e1d70ea5f5a9eb6dad9c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36989853e0d247e504b292e17d8a8cfb.png)
(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.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/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
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2018-03-19更新
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3卷引用:【全国百强校】甘肃省会宁县第一中学2018-2019学年高二上学期第一次月考数学试题
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解题方法
6 . 已知等差数列
的前
项和为
,
三点共线,且
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3ed16bc1ac15e077c44956797fa3de1.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/01225eca2322a6136314dedadcafa994.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cf5c7df02af9cc95810c0882fd4aeac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3ed16bc1ac15e077c44956797fa3de1.png)
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2017-10-17更新
|
1118次组卷
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5卷引用:甘肃省高台县第一中学2018届高三上学期第五次模拟(12月)数学(理)试题
7 . 在《张丘建算经》有一道题:“今有女子不善织布,逐日所织的布同数递减,初日织五尺,末一日织一尺,计织三十日,问共织布几何?”
A.![]() | B.![]() | C.![]() | D.![]() |
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2017-10-14更新
|
742次组卷
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6卷引用:甘肃省兰州市西北师范大学附属中学高三2018级一调理科数学试卷
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8 . 等差数列
的前
项和为
,且满足
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/554e6c461ccc5aa3093c524aa528a4e2.png)
![](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/6c499dacd2ddceb7704ce911871126f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/554e6c461ccc5aa3093c524aa528a4e2.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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2017-06-05更新
|
670次组卷
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2卷引用:甘肃省兰州第一中学2017届高三冲刺模拟考试数学(理)试题
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9 . 我国古代,9是数字之极,代表尊贵之意,所以中国古代皇家建筑中包含许多与9相关的设计.例如,北京天坛圆丘的底面由扇环形的石板铺成(如图),最高一层是一块天心石,围绕它的第一圈有9块石板,从第二圈开始,每一圈比前一圈多9块,共有9圈,则前9圈的石板总数是__________ .
![](https://img.xkw.com/dksih/QBM/2017/4/10/1662943482093568/1663436327960576/STEM/1d9d60bd-9218-4c3b-8afc-7440c0077ded.png)
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10卷引用:甘肃省张掖市2021-2022学年高二上学期期末数学(理)试题
甘肃省张掖市2021-2022学年高二上学期期末数学(理)试题2017届江西省高三4月新课程教学质量监测数学(文)试卷2017届江西省高三4月新课程教学质量监测数学(理)试卷黑龙江省哈尔滨师范大学附属中学2020-2021学年高二上学期开学考试数学(文)试题黑龙江省哈尔滨师范大学附属中学2020-2021学年高二上学期开学考试数学(理)试题四川省仁寿第一中学校南校区2020-2021学年高二上学期开学考试数学试题陕西省咸阳市实验中学2020-2021学年高二上学期第二次月考数学(文)试题江苏省苏州市张家港市梁丰高级中学2020-2021学年高二上学期期中数学试题(已下线)第四章 数列单元测试(基础卷)-2020-2021学年高二数学新教材单元双测卷(人教A版2019选择性必修第二册)(已下线)第4章 数列(新文化30题专练)2021-2022学年高二数学考试满分全攻略(人教A版2019选修第二册+第三册)
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10 . 已知等差数列
的前
项和为
,若
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d4f76b64c14b0b6c0f8c6c8af21011f.png)
![](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/3903653955c424d3f6135edc5b47e231.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3a5f81dc2879457e8a62cbb231c4a00.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d4f76b64c14b0b6c0f8c6c8af21011f.png)
A.36 | B.72 | C.144 | D.288 |
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2017-03-21更新
|
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8卷引用:2017届甘肃省兰州市高三第一次诊断性考试数学(理)试卷