1 . 已知数列
的前n项和为
.
(Ⅰ)若
为等差数列,求证:
;
(Ⅱ)若
,求证:
为等差数列.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(Ⅰ)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f70e63ef83ef4bfd67a54a44ce207889.png)
(Ⅱ)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f70e63ef83ef4bfd67a54a44ce207889.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
您最近一年使用:0次
2020-10-31更新
|
615次组卷
|
4卷引用:【全国百强校】四川省成都外国语学校2018-2019学年高一下学期期中考试理科数学试题
【全国百强校】四川省成都外国语学校2018-2019学年高一下学期期中考试理科数学试题四川省成都外国语学校2018-2019学年高一下学期期中考试文科数学试题陕西省汉中市五校2020-2021学年高二上学期第一次月考数学试题(已下线)专题3 等差数列的判断(证明)方法 微点1 定义法、等差中项法
解题方法
2 . 已知数列
为等差数列,其中:
.
(1)求数列
的通项公式;
(2)记
,设
的前
项和为
,求最小的正整数
,使得
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/067a384c2d5fb051d1b9a5970b3f4018.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50a813139b92a24e1124ef96e3e485f5.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/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0e3258f30333c342e40009fc4c168e8.png)
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3 . 已知公差不为0的等差数列
的首项
为a(
,且
),且
,
,
成等比数列.
(1)求数列
的通项公式;
(2)记
(
),求
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/22dd8b3dc4c609bab82d356a5cc2208d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20849c00c47cbdc43f18d53341b6c4e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/252de0a549286d1b1721ae96d5832654.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a03fee94205c63211128cbadfa17b810.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/762e892000e8cd7bd21057139658b278.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f728a87ce0612866fe520e5ea3f57f33.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f093c61867ee4ce75f951d46b9b123.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
您最近一年使用:0次
名校
解题方法
4 . 已知数列
的前
项和为
,满足
,
,数列
满足
,
,且
.
(1)求数列
的通项公式;
(2)求证:数列
是等差数列,求数列
的通项公式;
(3)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/c3ddd6d99ad32dd7fdb1797d8cf94786.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cea4ac187cbb465180e89f38250b3970.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36749152800d3226346fa4ccfa5bf2e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cea4ac187cbb465180e89f38250b3970.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59dd6c97d2ee3e74ba5730f1cbcc1d43.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
(2)求证:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f997e6d483c0d0990cb550bbde39fa9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c145ede47d16cc36fa56d2d32ae57c8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.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
5 . 已知等差数列
满足:
的前
项和为
.
(1)求
及
;
(2)求
为何值时
取得最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84eeaaf0527a2eaee160401223784f95.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
您最近一年使用:0次
名校
解题方法
6 . 已知等差数列
,公差d>0,前n项和为
,
,且满足
成等比数列.
(1)求
的通项公式;
(2)设
,求数列
的前n项和
的值.
![](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/36183db0759eec0e108274d229fcd00b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21eb2db5c8c4af7386e1cf10fd93b214.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf62e018d5136fd80adbd20808bcf0e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
您最近一年使用:0次
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7 . 已知等差数列
的前
项和为
,且满足
,
.
(1)求数列
的通项
及前n项和
;
(2)令
,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/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5db1e8083860d478547a6995697c393a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06abbb18b69a62ff1eb1a6da83702573.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(2)令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83a14c092f780da52a2bce7f2d4cda74.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
名校
解题方法
8 . 在等差数列
中,
,
.
(1)求数列
的通项公式;
(2)求数列
的前n项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00d194ba78838168b0e2dd321063d807.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5b0da4fcbf9ec484dd9444a18609065.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/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
您最近一年使用:0次
2020-08-30更新
|
536次组卷
|
6卷引用:四川省泸州市泸县第一中学2019-2020学年高一下学期期中考试数学试题
四川省泸州市泸县第一中学2019-2020学年高一下学期期中考试数学试题四川省珙县中学校2020-2021学年高一下期数学第5月月考测试题江西省丰城市第九中学2018-2019学年高一下学期期中考试数学试题安徽省宣城二中2019-2020学年高一下学期第二次月考理科数学试题(已下线)专题2.1等差数列及其求和(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)考点40 等差数列及其前n项和-备战2021年新高考数学一轮复习考点一遍过
名校
解题方法
9 . 已知等差数列
满足
.
(1)求
的通项公式;
(2)设等比数列
满足![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf20965455f0611eaf97b40d8d9fd926.png)
,求
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65392f607a0eb86fb35d643c2f8d5c1b.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)设等比数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf20965455f0611eaf97b40d8d9fd926.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dbcd03d9ffc473515485c1e6ff0e3840.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
2020-10-07更新
|
292次组卷
|
14卷引用:四川省攀枝花市第十五中学2019-2020学年高一下学期期中考试数学(理科)试题
四川省攀枝花市第十五中学2019-2020学年高一下学期期中考试数学(理科)试题四川省攀枝花市第十五中学2019-2020学年高一下学期期中考试数学(文)试卷四川省珙县中学校2020-2021学年高一下期数学第5月月考测试题广东省江门市第二中学2018-2019学年高一下学期第一次月考数学试题山西省长治市第二中学2018-2019高一下学期期末考试数学试题吉林省长春市第二十九中学2019-2020学年高一下学期期中考试数学试题宁夏长庆高级中学2020-2021学年高一下学期期末数学试题陕西省吴起高级中学2018-2019学年高二上学期期末考试数学(理)基础试题2陕西省吴起高级中学2018-2019学年高二上学期期末考试数学(理)基础试题1甘肃省天水市第一中学2019-2020学年高二下学期第一次学段考试数学(文辅班)试题甘肃省天水市第一中学2019-2020学年高二下学期第一次学段考试数学(文)试题广东省中山市卓雅外国语学校2020-2021学年高二上学期第一次段考数学试题苏教版(2019) 选修第一册 必杀技 第四章 素养检测黑龙江省哈尔滨市巴彦县第三高级中学2021-2022学年高二上学期期末数学试题
解题方法
10 . 已知等差数列
的前n项和为
,关于x的不等式
的解集为
.
(1)求数列
的通项公式;
(2)若数列
满足
,求数列
的前n项和
.
![](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/522bb59f912138a931673ab2813cc77b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16c6d785c3c09b9df343499dc11cadaa.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ff47ceb7948100fee79c24b0abae11e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
您最近一年使用:0次