设公比为正数的等比数列
的前
项和为
,已知
,数列
满足
.
(1)求数列
和
的通项公式;
(2)设数列
的前
项和为
,若不等式
恒成立,求
的最小值.
![](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/8d376d4f11c5e4b7a76ad5549ed11a28.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0f6000421c5370e4b89f23be199f388.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)设数列
![](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/897a62a7973b8ad082a8ae244afa8abb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
更新时间:2023-11-10 13:48:28
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相似题推荐
解答题-问答题
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适中
(0.65)
名校
解题方法
【推荐1】在等差数列
中,
,其前
项和为
,等比数列
的各项均为正数,
,公比为
,且
.
(1)求
与
;
(2)证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b13a6e1d671215fc96e4bee3541d1096.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/5fce83115a50f99e08e9a2db7267aeed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ebb35dc249ffbceca8e02c4e3937723a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86fde3541708c770e48a06c28f9a3434.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0540a7b1fee6be795e89e3e02e791b0.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/686ece75006ad358f23314dc8a246e11.png)
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05cc3cb89d22f3397ae441cd9dfa408a.png)
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【推荐2】若数列
满足
(
,p为常数),则称数列
为等方差数列,p为公方差.
(1)已知数列
,
,
,
分别满足
,
,
,
,从上述四个数列中找出所有的等方差数列(不用证明);
(2)若数列
是首项为1,公方差为2的等方差数列,求数列
的前n项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/595955aa3a2670abcd60c78a5086f2fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29d5ec9ad92f37e64eccce922ab1b14e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(1)已知数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38ef4c4439b36c2847b0056a116d56d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d813f3ca8db41a4db6c18eac30fef98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e976c0663fa749ca749f99842d21ca03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1165edc23b5782b5942ef7e79130bb94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ed3e9ffff5ee15df77acad96e5efd08.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48efe4d781c67e697b6f5876bdfb754b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9bd47610af84b5c2136f3f996cb60de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ecd353d6f74d3052b1a95dbf83d1704.png)
(2)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c806dc9bf2cad0cb20220d23bd252a2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
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【推荐1】已知等比数列
的前n项和为
,公比
,
,
.
(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/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f71acdb04454c77e1e25ad4f336cccfe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e86551283c9dfa1c39bdc9b0dd546803.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ea11bd18577ee314988bc70b0caf23f.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/b7079dd05a8d4e8e22b4c4fe54e9196e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
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解答题-问答题
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适中
(0.65)
名校
解题方法
【推荐2】已知首项为
,公比为
的等比数列
前
项和为
,若 ,是否存在互不相等的正整数
,使得
,
,
,成等差数列?若存在,求
;若不存在,请说明理由.
从(1)
(2)
这两个条件中任选一个,补充在上面问题中并作答.
注:如果选择多个条件分别解答,按第一个解答计分.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa8a716a31b0f51b70fdf9bdb257909.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/94bc90a5a5e21633f0dba39e78768adc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d0a9523f2084cf17b8656c11ab1d95e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a45163ab6dd6f8ca9f21cabfebcbe4cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83d6fa0e8afd0eab61974a529bf25e0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
从(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15bf68ebb978a28fe28021bed4a5efb8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95f2f209bf43dbe82e11852148ff507e.png)
注:如果选择多个条件分别解答,按第一个解答计分.
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【推荐1】已知数列
的各项均为正数,前n项和分别为
且对任意正整数,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/474e74adaecd18fa2457b0e40202a29e.png)
恒成立.
(1)分别求数列
的通项公式;
(2)若对于任意的正整数
恒成立,求实数k的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/942ed174dfdafaf5f0a68cac579110f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e5e1b15dadf55a261f4228544a9dce1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/474e74adaecd18fa2457b0e40202a29e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58f5cf5e0a43a83ed876a1f1f6f5ae48.png)
(1)分别求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/942ed174dfdafaf5f0a68cac579110f8.png)
(2)若对于任意的正整数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4460369c4d7d912cb569a6032cbdf0a5.png)
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【推荐2】在无穷数列
中,若存在
,对于
中的任意一项
,都有
成立,则称数列
为A数列,m称为该A数列的特征值.
(1)若无穷数列
是首项与公差都是1的等差数列,那么数列
是否为A数列?若是,求出该数列的特征值;若不是,请说明理由;
(2)若数列
是特征值为3的A数列,且
,用数学归纳法证明:对任意
且
,不等式
恒成立.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcd9218a657b17654c5d757a6f7dee9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04e77ec944548c3a2c1003d7dc1c1df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8973bfe15841a7a59c526e65beb3483.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(1)若无穷数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2459ac63473bac92d4d31a717f29d995.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0704f453b2de48d36911f7db496bbf82.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f093c61867ee4ce75f951d46b9b123.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca97d48944151b6c7219285a062cf9cf.png)
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【推荐3】我国南宋时期的数学家杨辉,在他1261年所著的《详解九章算法》一书中,用如图的三角形解释二项和的乘方规律.此图称为“杨辉三角”,也称为“贾宪三角”.在此图中,从第三行开始,首尾两数为
,其他各数均为它肩上两数之和.
![](https://img.xkw.com/dksih/QBM/2021/7/20/2768335173107712/2793988819877888/STEM/a4a2071e-d54b-4260-9d37-1942fb2a7a43.png?resizew=246)
(1)把“杨辉三角”中第三斜列各数取出按原来的顺序排列得一数列:
,
,
,
,
,…,写出
与
的递推关系,并求出数列
的通项公式;
(2)已知数列
满足
,设数列
满足:
,数列
的前
项和为
,若
恒成立,试求实数
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://img.xkw.com/dksih/QBM/2021/7/20/2768335173107712/2793988819877888/STEM/a4a2071e-d54b-4260-9d37-1942fb2a7a43.png?resizew=246)
(1)把“杨辉三角”中第三斜列各数取出按原来的顺序排列得一数列:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f8c4c029e552954bd493b49aeab82d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d07ae0b4264da6a8812454ffd2f20d94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58b184c94e38f1e5dbe750b2168c2a37.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2278c80ff61dc116fa918c177ee4704.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)已知数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/facb460ed1932a6416738667afe85230.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7759e794fb2ade6979c22342c72d7e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96b250e4276bf3f328b03a66765541f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c8bfb610cc10e7d25ef05df4bf706a48.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
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