解题方法
1 . 在等差数列
中,已知
,
与
的等差中项为
,等比中项为
,则通项公式![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3f7fda69e2b32b9ced2239f915fa59b.png)
________ ;前
项和![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04c2864e2ec3416cc4c081ac1f71a0af.png)
________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/065be21c20118f713d288f3a84ad114f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f65fc200f10b97588a0c9896277c9c64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8860d9787671b53b1ab68b3d526f5ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3f7fda69e2b32b9ced2239f915fa59b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04c2864e2ec3416cc4c081ac1f71a0af.png)
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2 . 在等差数列
中,
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dbd9ff686703cad03aa383e5fec21.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/605645034f708fd13ddddb872c4782a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dbd9ff686703cad03aa383e5fec21.png)
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3 . 若5是
与
的等差中项,3是
与
的等比中项,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2b1b96f5050de3bc7ae53c7bf0c21e8.png)
__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2b1b96f5050de3bc7ae53c7bf0c21e8.png)
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4 . 在等差数列
中,前
项和为
,若
,则
的值为_______ .
![](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/8b1d3a06ee3a948a439f482794c8540c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39d8594f325bb1c5d0f7e1080d32fa11.png)
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2024-01-17更新
|
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2卷引用:江苏省南京市2023-2024学年高二上学期期末考前模拟数学试题
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5 . 已知数列
是等差数列,
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a1febab872d9b3371f3e794657d3255.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047bb07874da00520acc13a9c1b1f929.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a1febab872d9b3371f3e794657d3255.png)
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2023-12-31更新
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3卷引用:安徽省滁州市明光市第三中学2023-2024学年高二上学期11月月考数学
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6 . 一个正实数的小数部分的2倍,整数部分和自身成等差数列,则这个正实数是______ .
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2023-12-29更新
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2卷引用:河南省南阳市2023-2024学年高三上学期期中数学试题
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7 . 若等差数列
的前m项的和
为20,前3m项的和
为90,则它的前2m项的和
为____________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1752474698cd5466dd180df0a00ba9c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fa209ac86cd8c88e638cda47db5bfa2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70ffd3e122e6c12db948aeedaea20fce.png)
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解题方法
8 . 各项均为正数的等比数列
的前
项和为
,且
,
,
成等差数列,若
,则
_____ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.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/cfaca09f4558cc263c62abd9f461683d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/049cbc3e23ca095e9a542a3401066673.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c1ccc6c74b8754e9bcbb3f39a11b6f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9620357ea5be4037cfdccd09a27d3862.png)
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2023-12-19更新
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5卷引用:重庆市渝北中学校2024届高三上学期12月月考数学试题
9 . 已知等比数列
的各项均为正数,且
成等差数列,则公比![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad0d99fef1aa4dbcc6dc7b30b7d2c9a9.png)
________ ,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7caae9d7f08e9dc13d97c2ca693886d.png)
________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3945136e6b10e840ae616d6f1471d73.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad0d99fef1aa4dbcc6dc7b30b7d2c9a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7caae9d7f08e9dc13d97c2ca693886d.png)
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2023-12-18更新
|
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4卷引用:人教A版(2019) 选修第二册 数学奇书 第四章 数列 4.3等比数列 4.3.1 等比数列的概念 第1课时 等比数列的概念与通项公式
人教A版(2019) 选修第二册 数学奇书 第四章 数列 4.3等比数列 4.3.1 等比数列的概念 第1课时 等比数列的概念与通项公式(已下线)第4.3.1讲 等比数列的概念(第1课时)-2023-2024学年新高二数学同步精讲精练宝典(人教A版2019选修第二、三册)(已下线)4.3.1 等比数列的概念——课后作业(巩固版)(已下线)4.3.2 等比数列的前n项和公式——课后作业(巩固版)
解题方法
10 . 设
是等差数列
的前
项和
,若
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adf14ebc775db2414a5a960badca8960.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)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdd2b9b337079cc29a9044a8c30f6814.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a3bf2f8745cd5d07ed9fcdce5f91909.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adf14ebc775db2414a5a960badca8960.png)
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2023-12-14更新
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