1 . 已知数列
的前
项和为
,
.
(1)若
是等比数列,且
,求
;
(2)若
,求
.
![](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/36183db0759eec0e108274d229fcd00b.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55e0508d698683f6d083733b26d81798.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/194f644d156cfa364378e6cb1796073b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d16765bfe96c4c2733afdf4099a33f5e.png)
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2023-08-09更新
|
553次组卷
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2卷引用:重庆市南开中学校2024届高三上学期7月月考数学试题
2 . 已知等差数列
的前
项和为
,
,
,求:
(1)
;
(2)若
、
、
成等比数列,求
.
![](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/127943cfb7bfdc1c3f5495b1f4f977cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79b50b3927041221a53f19b6a0549d71.png)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6899bf9cadae2ccdb14cbc87d4f280ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f1dc33cab9c1882ae0d33d5f0d047bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d0a9523f2084cf17b8656c11ab1d95e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
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名校
3 . 《九章算术》是我国古代内容极为丰富的数学名著,书中有如下问题:“今有女子善织,日益功,疾,初日织五尺,今一月织七匹三丈(1匹
尺,一丈
尺),问日益几何?”其意思为:“有一女子擅长织布,每天比前一天更加用功,织布的速度也越来越快,从第二天起,每天比前一天多织相同量的布,第一天织5尺,一月织了七匹一丈,问每天增加多少尺布?”若这一个月有29天,记该女子一个月中的第
天所织布的尺数为
,则
的值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/680ea1c4c8eb2642286e80e1349f8eab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a3c450315612a9fa3fc9562f290bc04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d2cf6ded10eb5826ecbfca3b40d81af.png)
A.15 | B.![]() | C.![]() | D.![]() |
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2023-01-18更新
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514次组卷
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2卷引用:重庆市第一中学校2022-2023学年高二上学期期末数学试题
名校
解题方法
4 . 已知正项等比数列
前
项和为
,且
成等差数列.
(1)求数列
的通项公式;
(2)记
,其前
项和为
,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/d3768db0f2e2881b810d44ddc39ff295.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdd07887b36d48702e6ab2096ec1cdf4.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e764296a62a7def78e39370f746b4663.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/6a40442811c08c432ec613102e4502c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87bd7d18f67e90a7c37fad4252e43c9d.png)
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2023-01-12更新
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739次组卷
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2卷引用:重庆市南开中学校2022-2023学年高二上学期期末数学试题
名校
解题方法
5 . 我校大礼堂舞台设备需要更换,设备采购费用为5万元,设备使用、检修等费用第一年为0.2万元,后逐年增长0.1万元,则本次采购设备使用___________ 年后停用,可使年均花费最小.
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解题方法
6 . 已知
是首项为19,公差为
的等差数列,
为
的前
项和.
(1)求通项
及
;
(2)设
是首项为1,公比为2的等比数列,求数列
的通项公式及其前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3edbd40e04e2a943051fa83d6e511add.png)
![](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/b6a24198bd04c29321ae5dc5a28fe421.png)
(1)求通项
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79768a4e3970a18741cee3fbd8bcbdad.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
7 . 已知等差数列
的前n项和为
,且
,则
的前15项和![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bca8f26c7e2cf5c7c4eaf39b089ae52.png)
______ .
![](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/5e6be3d08ff9d38039aaac8079cd2f44.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bca8f26c7e2cf5c7c4eaf39b089ae52.png)
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解题方法
8 . 已知数列
满足:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c06c14cb5b3224c917e8f30961803518.png)
(1)证明:数列
是等差数列;
(2)求数列
的前
项的和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c06c14cb5b3224c917e8f30961803518.png)
(1)证明:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70e1c06829bf8a351bf0d2d29d2889f1.png)
(2)求数列
![](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)
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2022-11-28更新
|
941次组卷
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4卷引用:重庆市第一中学校2022-2023学年高二上学期期中数学试题
9 . 已知数列
满足
,
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a7bf78468ca801ef305ce4f76986da1.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbe7bdaaf8b0adf10bf2ef6c1255b1dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f144864642c7e6f45de9569fd59e42e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a7bf78468ca801ef305ce4f76986da1.png)
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2卷引用:重庆市南开中学校2023届高三上学期第三次质量检测数学试题
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10 . 在等差数列
中,
,则数列
的前13项和为______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f696024e0013c43a1425e97e531d23b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
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