1 . 已知等差数列
的首项
为
,公差为
,在
中每相邻两项之间都插入两个数,使它们和原数列的项一起构成一个新的等差数列
.
(1)求数列
的通项公式;
(2)若
,
,…,
,…是从
中抽取的部分项按原来的顺序排列组成的一个等比数列,
,
,令
,求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/621604766ddd141c86e37da5e71aef26.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8860d9787671b53b1ab68b3d526f5ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f8c4c029e552954bd493b49aeab82d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/621604766ddd141c86e37da5e71aef26.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae8ebcd5b8f8ae04513834a70575816f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e3aaabba90eefb861068bf014f9d0b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b625d02d9054af978b5fb6ec9bee787.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2eaa992a449b828df0ff545e233b279b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f84f592310f4b9637b225cab622b2aa6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/661c88187badb79593cfec43cc641a81.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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2021-09-06更新
|
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4卷引用:山东省枣庄市滕州市第一中学2021-2022学年高三上学期10月月考数学试题
山东省枣庄市滕州市第一中学2021-2022学年高三上学期10月月考数学试题山东省青岛市2021-2022学年高三上学期开学考试数学试题山东省青岛市2021-2022学年高三上学期期初教学质量检测数学试题(已下线)江苏省南通市如皋市2022-2023学年高三上学期期初调研考前冲刺卷数学试题
2 . 已知
是等差数列,
是各项都为正数的等比数列,
,再从①
;②
;③
这三个条件中选择___________,___________两个作为已知.
(1)求数列
的通项公式;
(2)求数列
的前
项和.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07005f585f6faa46431e5ea7711ff510.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6fa3a7ce62e7bf557d9e1bf77c8dac0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46855749ad499de6801e4c0909a3edbf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af3fff17b6f8d3d05752501b9ef03fb4.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
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2021-02-04更新
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7卷引用:山东省枣庄市2020-2021学年高二上学期期末数学试题
山东省枣庄市2020-2021学年高二上学期期末数学试题(已下线)4.3.2 等比数列的前n项和公式(1) B提高练(已下线)【新教材精创】5.3.2 等比数列的前n项和 -B提高练 (原卷版)重庆市第八中学2021-2022学年高二上学期期末数学试题湖南省邵阳市新邵县2021-2022学年高二上学期期末质量检测数学试题黑龙江省齐齐哈尔市克东县第一中学等2校2022-2023学年高二下学期开学考试数学试题黑龙江省齐齐哈尔市讷河市第二中学等3校2022-2023学年高二下学期开学考试数学试题
3 . 在流行病学中,基本传染数
是指在没有外力介入,同时所有人都没有免疫力的情况下,一个感染者平均传染的人数.
一般由疾病的感染周期、感染者与其他人的接触频率、每次接触过程中传染的概率决定,假设某种传染病的基本传染数
,那么感染人数由1个初始感染者增加到1000人大约需要______ 轮感染?(结果取整数,初始感染者传染
个人为第一轮传染,这
个人再分别传染给
个人为第二轮传染……)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be9b4a83b9aebebf29de0c4406ebf894.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be9b4a83b9aebebf29de0c4406ebf894.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9b17c923943b7c49d42ce4b36293f78.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be9b4a83b9aebebf29de0c4406ebf894.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be9b4a83b9aebebf29de0c4406ebf894.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be9b4a83b9aebebf29de0c4406ebf894.png)
您最近一年使用:0次
4 . 等比数列
中,公比
,其前
项和为
,
,
.
(Ⅰ)求
的通项;
(Ⅱ)令
,求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eda6dc559d07bc22c9a0ed1e3a6d01d2.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/18d8e8f821111de8075e5c3dfb22a5d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/964df3e9308711d7e14fb624b0c25e2f.png)
(Ⅰ)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
(Ⅱ)令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c64a556380742743746b028dcb11dcf1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc33d79c18e3607d955295d08be1b800.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
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2021-01-10更新
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2卷引用:山东省枣庄市滕州市第一中学2021-2022学年高三上学期10月月考数学试题
名校
5 . 已知数列
,
满足
,
,
,
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/039e4fe671d61e59b96ee525c9df43e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59dd6c97d2ee3e74ba5730f1cbcc1d43.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2f96a186f776b1263e41d4692752d34.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/281bcb4fd55355866417d6348983e673.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/831ef77965032eeef6bf7ad7cdef029a.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
2020-03-09更新
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