1 . 已知a,b是异面直线,直线
且c不与b相交,求证:b、c是异面直线.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15234cbaac1f69fabb0abebda7709092.png)
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2 . 用反证法证明:
是无理数.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
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3 . (1)已知
为正数,
,
,用反证法证明:a,b中至少有一个不小于6;
(2)用分析法证明:当
时,
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b9cf5913674be8a7410df303a518062.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1cbacc1c7dbb5c5e40d1dea67959c93a.png)
(2)用分析法证明:当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0935b0d5568370418871fa7a6c47162d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be005ace3e23bdac0e3549c2b5543880.png)
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2023-05-10更新
|
79次组卷
|
4卷引用:陕西省咸阳市武功县2022-2023学年高二下学期期中文科数学试题
名校
4 . 如果实数
,且满足
,则称x、y为“余弦相关”的.
(1)若
,请求出所有与之“余弦相关”的实数
;
(2)若两数
、
为“余弦相关”的,求证:
;
(3)若不相等的两数
、
为“余弦相关”的,求证:存在唯一的实数
,使得x、z为“余弦相关”的,y、z也为“余弦相关”的.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edcb5a17cc44201beac4b0e0bd3a6118.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c4d191a06571223f167587fcc7b2299.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ec25b105130d71d3d529524671b6218.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
(2)若两数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3558a25771d7c5b73f0bcdefe7663fa9.png)
(3)若不相等的两数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35cb303f0057578ba50817087fe79b3a.png)
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2022-11-17更新
|
665次组卷
|
2卷引用:上海交通大学附属中学2022-2023学年高二上学期期中数学试题
名校
5 . 把1,2,…,10按任意次序排成一个圆圈.
(1)证明:一定可以找到三个相邻的数,它们的和不小于18;
(2)证明:一定可以找到三个相邻的数,它们的和不大于15.
(1)证明:一定可以找到三个相邻的数,它们的和不小于18;
(2)证明:一定可以找到三个相邻的数,它们的和不大于15.
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解题方法
6 . 已知数列
中
,其前
项和记为
,且满足
.
(1)求数列
的通项公式;
(2)设无穷数列
,
,…
,…对任意自然数
和
,不等式
均成立,证明:数列
是等差数列.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.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/f085575b5c456ae641143d2d430458b0.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7121ac4377ec9bcd071cb259678ab071.png)
(2)设无穷数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b715e7842b95f654f16056a7c7f2abe9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13423c094861baf4b759b7f3d8c3c226.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/686ece75006ad358f23314dc8a246e11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/402b8223a5be456f2acb45f65648eb34.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fce83115a50f99e08e9a2db7267aeed.png)
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2023-03-16更新
|
644次组卷
|
3卷引用:广东省韶关市武江区广东北江实验学校2022-2023学年高二下学期第一次(3月)月考数学试题
广东省韶关市武江区广东北江实验学校2022-2023学年高二下学期第一次(3月)月考数学试题(已下线)第4章 数列 单元综合检测(重点)-2023-2024学年高二数学同步精品课堂(沪教版2020选择性必修第一册)江苏省南京市中华、东外、镇江三校2022-2023学年高三下学期3月联考数学试题
名校
解题方法
7 . 已知
为有穷数列.若对任意的
,都有
(规定
),则称
具有性质
.设
.
(1)判断数列
是否具有性质
?若具有性质
,写出对应的集合
;
(2)若
具有性质
,证明:
;
(3)给定正整数
,对所有具有性质
的数列
,求
中元素个数的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78dab5f68d424caa15eb7686f8ac2249.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ae415a09c33aa3e9d1a3dab6c522dad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c7e9edf6d0468e0f8ca78b8bac63bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d7b740bc48c9718a294c11a1485fd14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3cfeacc29e6a61c5b3b4e439c0a91df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f21d7bf91134d8d08668cee5dacc2e8.png)
(1)判断数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cfd984b8eee88a2c10df0e883c9ef67f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e47cd514b2920609e3781c87df6ab70.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fed1adc648cc7d8fe7ac43df4b918f11.png)
(3)给定正整数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3cfeacc29e6a61c5b3b4e439c0a91df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
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2023-01-05更新
|
698次组卷
|
6卷引用:北京市第一六六中学2023-2024学年高二下学期3月月考数学试题
名校
解题方法
8 . 已知集合
,且M中的元素个数n大于等于5.若集合M中存在四个不同的元素a,b,c,d,使得
,则称集合M是“关联的”,并称集合
是集合M的“关联子集”;若集合M不存在“关联子集”,则称集合M是“独立的”.
(1)分别判断集合
与
是“关联的”还是“独立的”?
(2)写出(1)中“关联的”集合的所有的“关联子集”;
(3)已知集合
是“关联的”,且任取集合
,总存在M的“关联子集”A,使得
.若
,求证:
,
,
,
,
是等差数列.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de70a9c335265f5e4b61a2f7989e2e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8eeda5cef4846ef829069fe27f64e34e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcd60406fc788b81ef67654138b352c7.png)
(1)分别判断集合
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c44f95dd4daea270501b7c0bc0ac34f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e4de7b549ffad65410afe7e655df0c9.png)
(2)写出(1)中“关联的”集合的所有的“关联子集”;
(3)已知集合
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d7e475e8d3a456ec527868697ea17d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/498f92bf2e605cdbc91973e29b047566.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce4d89801d24aa43f47d6a366aad0571.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e1ccce8225324817b0577551956464f.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/f65fc200f10b97588a0c9896277c9c64.png)
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2022-05-02更新
|
609次组卷
|
2卷引用:北京理工附中2021-2022学年高二下学期期中考试数学试题
名校
解题方法
9 . 已知正项数列
,其前n项和
满足
.
(1)求证:数列
是等差数列,并求出
的表达式;
(2)数列
中是否存在连续三项
,
,
,使得
,
,
构成等差数列?请说明理由.
![](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/e044af159f37284bfc3451fbec1cb989.png)
(1)求证:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd8dfb2af5bfd44046042a50e6edc1c4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(2)数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f255d0395fba51ca2d44293cca42e0a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/217b927efe12a98e1082ecd7f035b921.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20751aac59514228826454c21803e504.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/871534dd012c891068fe7c9923ed4105.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f63b23a0fb3b23e25b629b854e21778.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/256f46087e5aa9602353f10da875928b.png)
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2022-03-30更新
|
2634次组卷
|
5卷引用:广东省汕头市金山中学2021-2022学年高二下学期期中数学试题
广东省汕头市金山中学2021-2022学年高二下学期期中数学试题浙江名校联盟2022-2023学年高二下学期期中联考数学试题(B卷)广东省2022届高三一模数学试题(已下线)必刷卷04-2022年高考数学考前信息必刷卷(新高考地区专用)(已下线)广东省2022届高三一模数学试题变式题17-22
解题方法
10 . 在
中,角
的对边分别为
且
.
(1)求证:
或
;
(2)若
成等差数列,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d5ef8b38961761228c4807b5acab9a9.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1cf290347a97b5fb9a9999ccf597bf6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03030ee2056e8fc3cf226a9e461fcd4e.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15ee608882881caff2f1e223177424ac.png)
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