名校
解题方法
1 . 已知数列
为等差数列,公差为
,前
项和为
.
(1)若
,求
的值;
(2)若首项
中恰有6项在区间
内,求
的范围;
(3)若首项
,公差
,集合
,是否存在一个新数列
,满足①此新数列
不是常数列;②此新数列
中任意一项
;③此新数列
从第二项开始,每一项都等于它的前一项和后一项的调和平均数.若能,请举例说明;若不能,请说明理由.(注:数
叫做数
和数
的调和平均数).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c02bc0c74292b1e8f395f90935d3174.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0c2d1a12d12803534db0e52cb194489.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08c9965a04c2a6de04e949a15762f372.png)
(2)若首项
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a79ad1addaf50a6159a55d9d0845a6fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65fee4e27b361e30d76db328b9048b49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c02bc0c74292b1e8f395f90935d3174.png)
(3)若首项
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae3012337aa392709349731fb1eef5b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c85144ca40f64972b8c94652f3926628.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6856c966ef5c9461552f681de2c48558.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b4dda7369edf57a39cfad583031328a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
您最近一年使用:0次
2023-02-08更新
|
538次组卷
|
2卷引用:辽宁省沈阳市辽宁实验中学北校2023-2024学年高二下学期4月阶段测试数学试题
名校
解题方法
2 . 已知数列
、
满足
,
,
.
(1)若
为等差数列,写出
的通项公式,并求所有正整数k的值,使得
;
(2)若
是公比2的等比数列,求证:
![](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/0ea8d0e50065114b05ef2dc1ea1129cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/385275d29d8c8a7841eaeaa3dfab2cdb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e06eb42f8c37fb46d0aa6f172fb21763.png)
(1)若
![](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/9eb5aa9071fdf573bedd5414ea115882.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fce260cc1d0788e48f79a6c40f346cf7.png)
您最近一年使用:0次
2022-02-23更新
|
922次组卷
|
3卷引用:辽宁省锦州市辽西育明高级中学2022-2023学年高二下学期第一次阶段性数学试题
名校
3 . 集合
,集合
,若集合
中元素个数为
,且所有元素从小到大排列后是等差数列,则称集合
为“好集合”.
(1)判断集合
、
是否为“好集合”;
(2)若集合
是“好集合”,求
的值;
(3)“好集合”
的元素个数是否存在最大值?若存在,求出最大值;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8be119f90345add00cd53fa449fe6f04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0672043affad9fdac675ce9dd823228.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b68df477b3ee45ac0f725db00d465a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c09b60535bb9fec40ebca4fb3f53adb0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
(1)判断集合
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62cc522867a8598c9a014c9eb33864e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4372e587e4438cd61dc2a564b68d01e.png)
(2)若集合
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ab0d982114b3cfb6e4316ae3b1c7c9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
(3)“好集合”
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
您最近一年使用:0次
2021-05-26更新
|
1034次组卷
|
5卷引用:辽宁省实验中学北校区2023-2024学年高二下学期期中测试数学试题
辽宁省实验中学北校区2023-2024学年高二下学期期中测试数学试题北京市海淀区2020-2021学年高二下学期数学期中试题上海市黄浦区2021届高三三模数学试题(已下线)第一章 集合(选拔卷)-【单元测试】2021-2022学年高一数学尖子生选拔卷(苏教版2019必修第一册)(已下线)数学-2022年高考押题预测卷03(北京卷)