1 . 已知数列
是公比为
的等比数列,若
,则
=( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa8a716a31b0f51b70fdf9bdb257909.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/467746ecd0a44a67d23357e8d465752d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa8a716a31b0f51b70fdf9bdb257909.png)
A.1 | B.![]() | C.1或![]() | D.1或![]() |
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2022-05-18更新
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4卷引用:新疆克孜勒苏柯尔克孜自治州2021-2022学年高一下学期期中考试数学试题
解题方法
2 . 设
是各项均为正数的等比数列,已知
=3,
是
与
的等差中项,
(1)求数列和
的通项公式;
(2)令
,求数列
的前n项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73f6aba03136f0c6d7c4de8f2a6e63b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f65fc200f10b97588a0c9896277c9c64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d1836a497061142f526cf7640a05e88.png)
(1)求数列和
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cf551f2c51760f4eaae782ddd64153f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
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2022-05-15更新
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2卷引用:新疆克孜勒苏柯尔克孜自治州2021-2022学年高一下学期期中考试数学试题
3 . 已知数列
的前
项和为
,且
.
(1)求
的通项公式;
(2)若
,求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.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/0964a1d6a3430614e6c556f2098cf4d8.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc63f57f0288776284440b3d3323dadc.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)
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2022-04-14更新
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5卷引用:新疆维吾尔自治区克孜勒苏柯尔克孜自治州2023-2024学年高三上学期11月期中考试数学试题
4 . 已知{an}是正项等比数列,且a1a8=4a5,a4与2a6的等差中项为18,则a5=( )
A.2 | B.4 | C.8 | D.16 |
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2019-05-29更新
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4卷引用:新疆克孜勒苏柯尔克孜自治州2021-2022学年高一下学期期中考试数学试题
新疆克孜勒苏柯尔克孜自治州2021-2022学年高一下学期期中考试数学试题【市级联考】四川省绵阳市2019届高三下学期第三次诊断性考试数学(理)试题(已下线)2019年9月17日《每日一题》必修5—— 等比数列的通项公式(已下线)专题6.3 等比数列及其前n项和(练)【理】-《2020年高考一轮复习讲练测》