名校
解题方法
1 . 已知数列
是公差
的等差数列,
的前
项和为
,
,
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5af1f1b7e9e20d799ee3c06b89a0611c.png)
______________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4ce64685821c3e55c07f151996ca8c3.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/1fc18c14fae04fc8f9ac9336dca2edb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e26faf2d524402fefa06823506d1971.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5af1f1b7e9e20d799ee3c06b89a0611c.png)
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2 . 我国的《洛书》中记载着世界上最古老的幻方:将1,2,…,9填入方格内使三行、三列、两条对角线的三个数之和都等于15,如图所示.
![](https://img.xkw.com/dksih/QBM/2020/8/23/2534260949229568/2542521152372736/STEM/b82154dbf3c7478e951d1981af12ffd7.png?resizew=274)
一般地,将连续的正整数1,2,…,
填入
个方格中,使得每行、每列、每条对角线上的数的和相等,这个正方形叫做
阶幻方.记
阶幻方的对角线上数的和为
,例如
,
,
,那么![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d5c12fa4f82f7a0cfd9d8f6b03bb63d.png)
______ .
![](https://img.xkw.com/dksih/QBM/2020/8/23/2534260949229568/2542521152372736/STEM/b82154dbf3c7478e951d1981af12ffd7.png?resizew=274)
一般地,将连续的正整数1,2,…,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ceef1abeeef220b4fe5f7d96feedd90.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/767f5a4746f04db68386fac3970b1ed1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dea30e7a3f7c68487d8bb224909b9455.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d6a5482f70366bced2a71ea1ed39192.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4ea3f6537473cb72da072ce46c31046.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08954cc7ad5ba3b93e5f58ece1f9d358.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d5c12fa4f82f7a0cfd9d8f6b03bb63d.png)
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2020-09-04更新
|
99次组卷
|
2卷引用:陕西省西安地区2020届高三下学期八校联考文科数学试题(B卷)
名校
3 . 已知
是各项均为正数的等比数列,
,
,
,则数列
的前10项和为_______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3bf75e900509aa73771677aeb81cb14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83d22eb5c5d00cac9198092b02075e76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0f6000421c5370e4b89f23be199f388.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
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4 . 数列1,-2,2,-3,3,-3,4,-4,4,-4,5,-5,5,-5,5,…,的项正负交替,且项的绝对值为1的有1个,2的有2个,…,
的有
个,则该数列第2020项是__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
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20-21高二·江苏·单元测试
5 . 在等差数列{an}中,若a5=
,8a6+2a4=a2,则{an}的前6项和S6的值为________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
您最近一年使用:0次
6 . 已知数列
为等差数列,
为其前n项和,
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adf14ebc775db2414a5a960badca8960.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/168def10ad26d180647138d33825ab34.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adf14ebc775db2414a5a960badca8960.png)
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2020-08-31更新
|
494次组卷
|
6卷引用:宁夏回族自治区银川一中2019-2020学年高一下学期期末考试数学试题
宁夏回族自治区银川一中2019-2020学年高一下学期期末考试数学试题(已下线)第02章章末复习课-2020-2021学年高二数学课时同步练(人教A版必修5)(已下线)第02章数列(A卷基础篇)-2020-2021学年高二数学必修五同步单元AB卷(人教A版,浙江专用)(已下线)第04章 章末复习课-2020-2021学年高二数学课时同步练(人教A版选择性必修第二册)(已下线)专题01 求等差数列和等比数列的基本量-2020-2021学年高二数学数列专题复习课(人教A版2019选择性必修第二册)甘肃省静宁县第一中学2020-2021学年高一下学期第三次月考数学(理)(实验班)试题
20-21高二·江苏·单元测试
解题方法
7 . 已知等差数列
的前n项和为
.若
,
,则
的值为________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43d799987e7af9561215baf4f99c7777.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42aab89e67736c81f63af477d8990dfd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05201ef79a5d5904f492845396fb5470.png)
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20-21高二·浙江·单元测试
8 . 设数列
的前n项和为
,若
,
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7999465d0e871febde66296a0cbf058c.png)
__________ ,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef354e5c5ff828cc8d27c71badd40f98.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/677e46ecd051c92489c0d1d458932f37.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cea4ac187cbb465180e89f38250b3970.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7999465d0e871febde66296a0cbf058c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef354e5c5ff828cc8d27c71badd40f98.png)
您最近一年使用:0次
名校
9 . 已知等差数列
的前n项和为
.若
与
的等差中项为8,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff6d838c156e98b50813db582fcf7aac.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69b0ab0ce90bc7f395e8f7fcbd549b15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f65fc200f10b97588a0c9896277c9c64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff6d838c156e98b50813db582fcf7aac.png)
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2020-08-24更新
|
295次组卷
|
5卷引用:江苏省泰州市2019-2020学年高三上学期期中数学试题
江苏省泰州市2019-2020学年高三上学期期中数学试题江苏省盐城市第一中学2020届高三下学期6月第二次调研考试数学试题(已下线)专题11 等差数列和等比数列-2020年高考数学母题题源解密(江苏专版)江苏省2020届高三高考数学考前最后押题(一)(已下线)第04章 数列(A卷基础卷)-2020-2021学年高二数学选择性必修第二册同步单元AB卷(新教材人教A版)
10 . 记数列
的前
项和为
,若
,
,
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06fbdd2e3efbef1ff014df55b242eced.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/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7a516778eeb77701ac6fa833b0edf5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/531faec6b55a0d6dee48be2c0d8c2758.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06fbdd2e3efbef1ff014df55b242eced.png)
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