1 . 设正整数
均不大于21,且每两个数的和不等于21.试求出所有满足条件的数组
的积
的和.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b094ffbd5f04c369ef661c7de169700.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b094ffbd5f04c369ef661c7de169700.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0a981b450ee8317005a613a031d2a6c.png)
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名校
2 . 已知a、b、c、d都是区间[1,2]上的实数,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4896478fbf813154d13650b48525178d.png)
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3 . 证明对所有的正整数
,存在一个集合
,满足如下条件:
(1)
由都小于
的
个正整数组成;
(2)对
的任意两个不同的非空子集
、
,集合
中所有元素之和不等于集合
中所有元素之和.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5818ede14d21f6df9ef9c2bfe09286c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9f1ad18371ec533aeac27cf1fad95c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
(2)对
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
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4 . 实数
、
、
满足
,试求
的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6592ff257bea95dc4d4cc898bde480f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a913cd07a8931a037ec8bf0350705ba2.png)
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5 . 已知数列
满足:
,
,
.求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61f75723824158fae6941098197f51b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7d996de3c21f0fbec3750b1985fc6c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b871ed324a95d6c6daf03fda30feb9b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d39d6aa1813347686313bc667026d52.png)
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6 . 已知圆
与曲线
,
,
,
为曲线
上的两点,使得圆
上任意一点到点
的距离与到点
的距离之比为定值
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79382ba44ba669b5d43fdd5427adf16c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bcc98b5b2112dfdcd62bba31da42593d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a66c5f00b5b38a2d052354b5611970e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fd03f39d3623265bdb636552d5f1041.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a4579ea783c518a9b3974ba64b0d236.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2781714853ddd3675560abfaa967242.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
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2011高三·山东·竞赛
7 . 集合
.如果
满足:其任意三个元素
、
、
,均有
,则称
具有“性质
”.为方便起见,简记
.具有性质
的所含元素最多的集合称为“最大集”.试问:具有性质
的最大集共有多少个?并给出证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2518c1b7966af15a1bb9b826af00c1d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c56898fd9497027b0fdfbc82446bfec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6c5d7591cb25c3ef3f326992f1c113b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
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8 . 甲乙两人进行某种游戏比赛,规定:每一次胜者得1分,负者得0分;当其中一人的得分比另一人的得分多2分时即赢得这场游戏,比赛随之结束.同时规定:比赛次数最多不超过20次,即经20次比赛,得分多者赢得这场游戏,得分相等为和局.已知每次比赛甲获胜的概率为可
,乙获胜的概率为
.假定各次比赛的结果是相互独立的,比赛经
次结束.求
的期望
的变化范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29c8578f06897aa6fb84aa95c797d3d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de7f9aeca52db1f0a9f7f164fa23cbcb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33470bee4febd946d39f7b63d6344c8f.png)
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9 . 某年级
位同学参加语文和数学两门课的考试,每门课的考分从0到100分. 假如考试的结果没有两位同学的成绩是完全相同的(即至少有一门课的成绩不同). 另外,“甲比乙好”是指同学甲的语文和数学的考分均分别高于同学乙的语文和数学的考分. 试问:当
最小为何值时,必存在三位同学(设为甲、乙、丙),有甲比乙好,乙比丙好.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
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