解题方法
1 . 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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2 . 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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3 . 设是
的充分不必要条件,
是
的必要不充分条件,则( )
A.![]() ![]() | B.![]() ![]() |
C.![]() ![]() | D.![]() ![]() |
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解题方法
4 .
为正实数,满足
,求
的最大值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/751e274e9107d780c39ba9c49d6daefb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c19cb3b888b46a0c5e62ccbb09bd77ba.png)
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解题方法
5 . 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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6 . 设,则
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7 . 设A在曲线
上,B在直线
上,O为坐标原点,则
的最小值是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4addacfadd6fac93f7323ce91e12005e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66d6e08526a91f8dfd160e7da2f92a3a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a704469569b68ee11ab166dba3f686f0.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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解题方法
8 . 如图,已知三棱柱
,
平面
.D,E分别是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/22/03e0cf8e-497b-4d52-a9f4-08f68e020eed.png?resizew=177)
(1)证明:
平面
;
(2)设
与平面
所成角的大小是
,若
,证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d1d2e0f281222a5f289ea4008370aed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1cc117eb1a2d0ea7123b2ca898547546.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/310e5cf87aa443ca7f0ff80aba6dddc4.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/22/03e0cf8e-497b-4d52-a9f4-08f68e020eed.png?resizew=177)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/063510e3c1fb6a7ccc3b8e3e3c7d660e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99b16cff607cdc2d69afc70dc778acbb.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24bb49fdc6b6bbb2449fdf8a0de769d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24a8670759c61d785b9a336885df700b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb2cf0e95fdf1fd8a5b01d3dfd905e08.png)
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解题方法
9 . 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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解题方法
10 . 设
,
,
,则( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b51358c6fd18265f9e3eb8a251bdeb63.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d13ac5fd914eb4f6d6be440255ed5f6e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d24a4a2ddd7e3bc197149ec67fc5b56b.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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