1 . 对于数列
,
,
,
,若满足
,则称数列
为“
数列”.
若存在一个正整数
,若数列
中存在连续的
项和该数列中另一个连续的
项恰好按次序对应相等,则称数列
是“
阶可重复数列”,
例如数列
因为
,
,
,
与
,
,
,
按次序对应相等,所以数列
是“
阶可重复数列”.
(1)分别判断下列数列
,
,
,
,
,
,
,
,
,
.是否是“
阶可重复数列”?如果是,请写出重复的这
项;
(2)若项数为
的数列
一定是“
阶可重复数列”,则
的最小值是多少?说明理由;
(3)假设数列
不是“
阶可重复数列”,若在其最后一项
后再添加一项
或
,均可使新数列是“
阶可重复数列”,且
,求数列
的最后一项
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/140b9dbcada4ac2e5fe3cc30009bcd67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daa5e9bd516f6282483b92cfe6074623.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68d510af048d3653f24e66afab88f406.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a359f9aeb5add5377519c6f7650ae6f.png)
若存在一个正整数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c99b42a8d33ca4eb4acadcf8b185db2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
例如数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ece6396ab53aabd0329992cc95ff407.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c1ccc6c74b8754e9bcbb3f39a11b6f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daf464629fa321a6ff7401ab79f07083.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daf464629fa321a6ff7401ab79f07083.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f65fc200f10b97588a0c9896277c9c64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5da4cd81500bdb43118150dbdb1541e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7fd71bc7e6668f90f259ad0b06dd60c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8860d9787671b53b1ab68b3d526f5ca.png)
(1)分别判断下列数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f344a2d8d76fad8cbecaffc44f11f907.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c95b6be4554f03bf496092f1acdfbb89.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c95b6be4554f03bf496092f1acdfbb89.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c95b6be4554f03bf496092f1acdfbb89.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
(2)若项数为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
(3)假设数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/681ae1522a36768618f7ddaf74abbb7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c95b6be4554f03bf496092f1acdfbb89.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad2da0ff9dc73d62f8162fc3de186150.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/681ae1522a36768618f7ddaf74abbb7e.png)
您最近一年使用:0次
2 . 设数列
,若存在常数
,对任意正数
,总存在正整数
,当
,有
,则数列
为收敛数列.下列关于收敛数列正确的有( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e976c0663fa749ca749f99842d21ca03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11bc05f41215f9894e11d1df0465751a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65fe91daf4622edddc49cf828e132432.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3799238799b6a61400032f588e681b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e976c0663fa749ca749f99842d21ca03.png)
A.等差数列不可能是收敛数列 |
B.若等比数列![]() ![]() |
C.若数列![]() ![]() ![]() |
D.设公差不为0的等差数列![]() ![]() ![]() ![]() |
您最近一年使用:0次
2020-11-14更新
|
312次组卷
|
3卷引用:专题09 《数列》中的存在性问题-2021-2022学年高二数学同步培优训练系列(苏教版2019选择性必修第一册)
(已下线)专题09 《数列》中的存在性问题-2021-2022学年高二数学同步培优训练系列(苏教版2019选择性必修第一册)江苏省盐城市2020-2021学年高三上学期期中数学试题江苏省南通市海安县曲塘中学2020-2021学年高二上学期阶段性测试二数学试题
20-21高二·江苏·假期作业
3 . 记无穷数列{an}的前n项a1,a2,…,an的最大项为An,第n项之后的各项an+1,an+2…的最小项为Bn,bn=An﹣Bn.
(1)若数列{an}的通项公式为an=2n2﹣7n+6,写出b1,b2,b3;
(2)若数列{bn}的通项公式为bn=﹣2n,判断{an+1﹣an}是否为等差数列,若是,求出公差;若不是,请说明理由;
(3)若数列{bn}为公差大于零的等差数列,求证:{an+1﹣an}是等差数列.
(1)若数列{an}的通项公式为an=2n2﹣7n+6,写出b1,b2,b3;
(2)若数列{bn}的通项公式为bn=﹣2n,判断{an+1﹣an}是否为等差数列,若是,求出公差;若不是,请说明理由;
(3)若数列{bn}为公差大于零的等差数列,求证:{an+1﹣an}是等差数列.
您最近一年使用:0次
解题方法
4 . 对于数列
,若存在数列
满足
,则称数列
是数列
的“倒差数列”,以下对“倒差数列”描述正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ba3930baa4fd2e0b2bbb97cc6532986.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
A.若数列![]() |
B.若数列![]() ![]() |
C.若数列![]() ![]() |
D.若数列![]() ![]() |
E.若数列![]() ![]() |
您最近一年使用:0次
5 . 已知数列
是无穷数列,
(
是正整数),
.
(1)若
,写出
的值;
(2)已知数列
中
,求证:数列
中有无穷项为1;
(3)已知数列
中任何一项都不等于1,记![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c82ad4661d43b78ced103bc330f94c2.png)
,
为
较大者).求证:数列
是单调递减数列.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/894aaec56149f880c7cf2bbc0f358d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/605a541d2605634ffa4270b7a7b8ebf5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632244ea6931507f8656e1cc3437d392.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0d9c454438b226f43f913a9a63abf04.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91d38d184da2ba1c9d4630a72e02ab57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2ef8f3a003fc34b75b71e5b6992cee6.png)
(2)已知数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/894aaec56149f880c7cf2bbc0f358d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1addfcbb96872d7822ec9729b50a5b0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/894aaec56149f880c7cf2bbc0f358d2b.png)
(3)已知数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/894aaec56149f880c7cf2bbc0f358d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c82ad4661d43b78ced103bc330f94c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/075be98c10422c247c7ed3e3fe87ce31.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c75fa2b1145fa7a2024fac218dbe4f94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/280860dd039e1305a5ccc455f63e8223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fce83115a50f99e08e9a2db7267aeed.png)
您最近一年使用:0次
6 . 已知
均为非负实数,且
.
证明:(1)当
时,
;
(2)对于任意的
,
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4099e1919c5450fd97590c4858c2d37c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81224c37d3740e35f03d6ff902adfe24.png)
证明:(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fac3649308b528fd56545ba102dc42d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7d48e59fe8e97b6d8323bfe778e7bcc.png)
(2)对于任意的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c154ab0e89e6303f44aaeecf959454ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3f71ffa702e15a1a7cfd815463d49a2.png)
您最近一年使用:0次
2020-02-25更新
|
306次组卷
|
2卷引用:专题20 数学归纳法及其证明-《巅峰冲刺2020年高考之二轮专项提升》[江苏]
名校
7 . 若数列
满足:
增大时,
无限接近
,则称数列
是黄金数列.满足下列条件的数列
是黄金数列的是( )
![](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/17da60ba436bb74c1549818280dd052a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0c7189a018c932a7f3fb077aba97e8b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
A.![]() ![]() ![]() | B.![]() |
C.![]() | D.![]() |
您最近一年使用:0次
2021-01-28更新
|
196次组卷
|
3卷引用:4.3.1 等比数列的概念-2021-2022学年高二数学同步培优训练系列(苏教版2019选择性必修第一册)
(已下线)4.3.1 等比数列的概念-2021-2022学年高二数学同步培优训练系列(苏教版2019选择性必修第一册)河南省沈丘县第一高级中学2020-2021学年高三尖子生12月调研考试数学(理)试题河南省沈丘县第一高级中学2020-2021学年高三尖子生12月调研考试数学(文)试题
解题方法
8 . 各项为正数的数列
如果满足:存在实数
,对任意正整数n,
恒成立,且存在正整数n,使得
或
成立,则称数列
为“紧密数列”,k称为“紧密数列”
的“紧密度”.已知数列
的各项为正数,前n项和为
,且对任意正整数n,
(A,B,C为常数)恒成立.
(1)当
,
,
时,
①求数列
的通项公式;
②证明数列
是“紧密度”为3的“紧密数列”;
(2)当
时,已知数列
和数列
都为“紧密数列”,“紧密度”分别为
,
,且
,
,求实数B的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2397df3279607612ea3cbef101ee0bf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc9dd0fff52e661d24556933e0b2fb13.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcbb3965c6d873ee274a572f7b28f544.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b91d28481ee7422fe0d91669dce697a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.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/2b0b5f7c8a883316d64855f17e71942c.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62e4de71feae82210ab5a2f5627002bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f60c30cc5b059aac0e6fa6dd3a5dc943.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac88e202c8f32621171f010ccfceba67.png)
①求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
②证明数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/601a4fe4960f18539e153430f5078b69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/846fa57d92d6ad44d6a0cafad1e71ed4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6defc43285a40f7ccb74c1cc04265eba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/423b7ae39db552e60ee8b1d27312306f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6defc43285a40f7ccb74c1cc04265eba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9049dd395a386fe8e30320f3f2abd28f.png)
您最近一年使用:0次
9 . 设数列
的前
项积为
.若对任意正整数
,总存在正整数
,使得
,则称数列
是“R数列”.
(1)若数列
的前n项积
(
),证明:
是“R数列”;
(2)设
是等比数列,其首项
,公比为
.若
是“R数列”,求
的值;
(3)证明:对任意的等比数列
,总存在两个“R数列”
和
,使得
(
)成立.
![](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/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0137430ff7d1753310cf17a5f0e58b57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
(1)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d6c5550de5e09dc151a9544ff4ee69f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36b98ef143f8159f3a7dafa1fd2f2370.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
(2)设
![](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/9aa8a716a31b0f51b70fdf9bdb257909.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa8a716a31b0f51b70fdf9bdb257909.png)
(3)证明:对任意的等比数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fce83115a50f99e08e9a2db7267aeed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38ef4c4439b36c2847b0056a116d56d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbdba786bfcefae56c61d6c9b6650d21.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36b98ef143f8159f3a7dafa1fd2f2370.png)
您最近一年使用:0次
2019高三·江苏·专题练习
10 . 若在数列
中,对任意正整数
,都有
(常数),则称数列
为“等方和数列”,称
为“公方和”,若数列
为“等方和数列”,其前
项和为
,且“公方和”为
,首项
,则
的最大值与最小值之和为________ .
![](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/667a9cf4b697d3c115b1805bcb6d8b89.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](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/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3d5611c524c9abbcb4c9c1eb04a3791.png)
您最近一年使用:0次