等差数列
的前n项和为
,已知
.
(1)求
的通项公式及
;
(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/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd909e4e623f8da2caad3fda1d76085b.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
(2)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e9135b87440cf6ff7e06df7853b3755.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
2021·广西·模拟预测 查看更多[3]
广西2021届高三高考模拟数学(文)试题(已下线)考点21 等差数列及其前n项和-备战2022年高考数学(文)一轮复习考点帮(已下线)第七章 数列专练7—分组、并项求和(大题)-2022届高三数学一轮复习
更新时间:2021-06-05 22:56:27
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相似题推荐
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】在①
,
;②
;③
,
.从这三个条件中任选一个填入下面的横线上并解答.
已知数列
是等差数列其前
项和为
,
,若_________.(注:如果选择多个条件分别解答,按第一个解答计分.)求数列
的通项公式;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae2e6956e0073cef684fef6a16bead0a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cde13a1d82174255f34cc22f8127787b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8bbb03e9f93969580c6f07667c209779.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9645bd4d2002993b90ec6d48f9c04f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c07ba166ca9af1ffde9dd49876b17a4.png)
已知数列
![](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/36b98ef143f8159f3a7dafa1fd2f2370.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
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【推荐2】已知等差数列{an}的前n项和为Sn,数列{bn}满足:点(n,bn)在曲线y=
上,a1=b4,___,数列{
}的前n项和为Tn.
从①S4=20,②S3=2a3,③3a3﹣a5=b2这三个条件中任选一个,补充到上面问题的横线上并作答.
(1)求数列{an},{bn}的通项公式;
(2)是否存在正整数k,使得Tk>
,且bk>
?若存在,求出满足题意的k值;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fbd367b4d805ece55cfef0ce146bab9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dfce215f34f701ee7c2cd2889a50f3f1.png)
从①S4=20,②S3=2a3,③3a3﹣a5=b2这三个条件中任选一个,补充到上面问题的横线上并作答.
(1)求数列{an},{bn}的通项公式;
(2)是否存在正整数k,使得Tk>
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb10f418620f7be1f8c7e94fb0b7a0fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ca8b26c3ad6d892590290a2304126bd.png)
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【推荐1】已知数列
是公比为
的等比数列,且满足
,
,
成等比数列,
为数列
的前
项和,且
是
和
的等差中项,求数列
的前
项和.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4844ada5b5eb39d704345bb4e6080d99.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8860d9787671b53b1ab68b3d526f5ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daf464629fa321a6ff7401ab79f07083.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7fd71bc7e6668f90f259ad0b06dd60c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.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/686ece75006ad358f23314dc8a246e11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5344eadd4711db34e3f935aedd5fb270.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
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解答题-问答题
|
适中
(0.65)
名校
解题方法
【推荐2】已知
,无穷数列
的首项
,如果
(
且
),
(1)若数列
是等差数列,求首项a的取值范围;
(2)求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c861222d17079fd174cd5b71a0eda38.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7fab51121848ce166035ceab6f4e00b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbc5ac1542da56851d19240e723a1530.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65a40142c84be68ee2918c3a8303388c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0704f453b2de48d36911f7db496bbf82.png)
(1)若数列
![](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/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】已知在递增等差数列
中,
,
是
和
的等比中项.
(1)求数列
的通项公式;
(2)若
,
为数列
的前
项和,当
对于任意的
恒成立时,求实数
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/039e4fe671d61e59b96ee525c9df43e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c1ccc6c74b8754e9bcbb3f39a11b6f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc858b7a95c5006a44067022da09f667.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/233b9b5a6ad66ad6da1ee66ae95de7b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.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/da46c52711fbde54c6f1260f5de02792.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e145b6046bc80d0ffecc61ac67c87ca1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
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【推荐2】在数列
中,
.
(1)证明:数列
是等比数列.
(2)设
,记数列
的前
项和为
,若对任意的
恒成立,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e0c2fe01c8a59da039b855ece3f2e20.png)
(1)证明:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c7d94406136605c5bc9cd9295d6c9fa.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dadad307a412db95933c9daa318667f8.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)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4a452d293890567b113999c9a52a8fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
您最近一年使用:0次
【推荐1】已知数列
的前
项的和为
,且
.
(1)求证:数列
是等比数列;
(2)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/2ead8921a4b8315ef84a8956b2c1cbac.png)
(1)求证:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97c033d0d59a0767eea50d0afa4737e4.png)
(2)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0496f142d8ae5acb06e83526eaa3ef87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
您最近一年使用:0次
【推荐2】已知数列
是等差数列,满足
,
,数列
是首项为1的等比数列,且
,
,
成等差数列.
(1)求
,
的通项公式;
(2)设
,求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be0d1a492ec22f4ca2372e2c59c61d6c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79b50b3927041221a53f19b6a0549d71.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0eeacc31bfbd4c536bb52bbaec43dd3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a8aada7b854c906305d0747c33f9929.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57483e04fd1840c87ac5325157149877.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d44ddab6e0c60119be69985ae7fa65b.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/1f7c445e0b95cd5f4675706e007206c2.png)
您最近一年使用:0次