1 .
,求所有的
,使得
中有无穷多项为正整数.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fad039ab9ca99b3d62b798884e8988b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/629507dcfdeb6866da428c4f45e2b21d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
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解题方法
2 .
是从
中随机抽取3个不同的数排列出的最大的三位数,
是从
中随机抽取3个不同的数排列出的最大的三位数.求
的概率.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9faa718b750cd0be91d5d9b76f948de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a829fdd8ec0f3b7ede883cf2c3e53b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c804bc27c6d7423946410c8a98db66bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae370cd09065372355be1ba7b78e6423.png)
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3 . 求所有正整数
,满足正
边形能内接于平面直角坐标系
中椭圆
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8715a3f984d2627afd7c40c61347b7cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ee31829d0d4d5f779a957d7df8058ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48da128547c4cf9745e8e4b99988a3db.png)
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4 . 将正整数
填入
方格表中,每个小方格恰好填1个数,要求每行从左到右10个数依次递减,记第
行的10个数之和为
. 设
满足:存在一种填法,使得
均大于第
列上的10个数之和,求
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/deacb2d14b3b685334af74c9eb08e708.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f23f3b42cd6069f0e461035e76459ee4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c05b9832b09731a574d4a4adf7448de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1aba753aa5e77c45b0d328c036a954a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70e72518ba0d330df05786f6c48db9b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/77efd8c62dacd2212c3ff5db6b02a5dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
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解题方法
5 . 如果
是离散型随机变量,则
在
事件下的期望满足
其中
是
所有可能取值的集合.已知某独立重复试验的成功概率为
,进行
次试验,求第
次试验恰好是第二次成功的条件下,第一次成功的试验次数
的数学期望是__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa0010cb466163db1349fc1040f6b439.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90a71f2ff30791e8b210727912600096.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97ad71223cc853bc21bf203e7a5321f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/385f040f4037e9934620d6971da08131.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
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6 . 校乒乓球锦标赛共有
位运动员参加.第一轮,运动员们随机配对,共有
场比赛,胜者进入第二轮,负者淘汰.第二轮在同样的过程中产生
名胜者.如此下去,直到第n轮决出总冠军.实际上,在运动员之间有一个不为比赛组织者所知的水平排序,在这个排序中
最好,
次之,…,
最差.假设任意两场比赛的结果相互独立,不存在平局,且
,当
与
比赛时,
获胜的概率为p,其中![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a998c92f966aae015d3e1e37c967e7b5.png)
(1)求最后一轮比赛在水平最高的两名运动员
与
之间进行的概率.
(2)证明:
,
为总冠军的概率大于
为总冠军的概率.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f31971306914638e5ceb1bbe437535d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9f1ad18371ec533aeac27cf1fad95c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49cc8f06c961b64b15a90b99f7adc604.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c814128ea2139e33db94ea590e7c2223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aec19b68e3add9d5bfcc6269a1855b87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3282e5fde4ae53fcb1bb072a685304c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/519321dbfc38d9b89948762478f71d0f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9454ddb2d570f884b15bd3ddf2a4545d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec6ba141730fd5aae78ada1a8eb17d21.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97ea8f47d8d8d9e1832d52b1c7425450.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a998c92f966aae015d3e1e37c967e7b5.png)
(1)求最后一轮比赛在水平最高的两名运动员
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c814128ea2139e33db94ea590e7c2223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aec19b68e3add9d5bfcc6269a1855b87.png)
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2eae64cb0b1c5e4f556e0ee0ca54fa9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97ea8f47d8d8d9e1832d52b1c7425450.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5654866bd68198db845fb43c6b4c858.png)
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解题方法
7 . 双五棱锥是由两个侧面均为边长为1的正三角形的五棱锥上下拼接而成的,如图所示.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/17/7b4e1fa0-9c3c-43ca-b5b3-188c8bc7d378.jpg?resizew=133)
(1)求双五棱锥的内切球半径;
(2)求分别位于拼接面(正五边形)两侧的相邻的两个正三角形构成的二面角的余弦值.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/17/7b4e1fa0-9c3c-43ca-b5b3-188c8bc7d378.jpg?resizew=133)
(1)求双五棱锥的内切球半径;
(2)求分别位于拼接面(正五边形)两侧的相邻的两个正三角形构成的二面角的余弦值.
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解题方法
8 . 在四面体
中,
为
中点,
为
外接球的球心,
.
(1)证明:
;
(2)若
,求四面体
体积的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a351136b18bc7d3bd5122332772ab23b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a351136b18bc7d3bd5122332772ab23b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0398ca118304f21b6fc3c36ecf8bf2f4.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab17db0e6518d617247e17afd313a6a2.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/578b12f739ef7fc54c65b8435b3c16aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af286347445bc77ba5dc6efb5fcc5b8f.png)
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9 .
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc6a0713917c995c9cba31fdab2bd766.png)
A.![]() | B.0 | C.1 | D.2 |
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10 . 某考试评定考生成绩时,采取赋分制度:只有原始分排名前3%的同学才能赋分97分及以上.若这些学生的原始分的最大值为a,最小值为b,令
为满足
的一次函数.对于原始分为
的学生,将
的值四舍五入得到该学生的赋分.已知小赵原始分96,赋分100;小叶原始分81,赋分97;小林原始分89,他的赋分是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5137f9fc50b56eeef9bd5ea9801eb87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc815c63d1205c123a0e267f9434e34e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
A.97 | B.98 | C.99 | D.98或99 |
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