解题方法
1 . 在某项投资过程中,本金为
,进行了
次投资后,资金为
,每次投资的比例均为x(投入资金与该次投入前资金比值),投资利润率为r(所得利润与当次投入资金的比值,盈利为正,亏损为负)的概率为P,在实际问题中会有多种盈利可能(设有n种可能),记利润率为
的概率为
(其中
),其中
,由大数定律可知,当N足够大时,利润率是
的次数为
.
(1)假设第1次投资后的利润率为
,投资后的资金记为
,求
与
的关系式;
(2)当N足够大时,证明:
(其中
);
(3)将该理论运用到非赢即输的游戏中,记赢了的概率为
,其利润率为
;输了的概率为
,其利润率为
,求
最大时x的值(用含有
的代数式表达,其中
).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c41d793c851a2f72f787913ba23e459c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a22baa009d2d45f6a37332ec3363285.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/903d7f7559c216e2516b9886c8f96008.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e60c0d3a709196db0791a93ed0db409.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf99487d7860d017c0747ff966edfd77.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cad52924df9291d5d191d18e09374ee1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6cdff4a44b674e8060072b7326549bf0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e60c0d3a709196db0791a93ed0db409.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fdbd2aa0b04224ad335d43a53d81ae16.png)
(1)假设第1次投资后的利润率为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2858005b9ae89ae080d83dcc13cf8e81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97c01fdc7bc471af0b264a04aef0823e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97c01fdc7bc471af0b264a04aef0823e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c41d793c851a2f72f787913ba23e459c.png)
(2)当N足够大时,证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f58c4f5f1d988a104655727aa501683c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd8f40e552f049c19252845917375c17.png)
(3)将该理论运用到非赢即输的游戏中,记赢了的概率为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2708fa6298e52f617383efc175b71ddc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2858005b9ae89ae080d83dcc13cf8e81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b9cb8e6ff801523b0304576cd69fd2d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b3e95410f3b4fcb0cba425b521d1f67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5092000864ee720978d6d701c953a388.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1938c5439464042af3cbd35cf65be156.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85a89183e464e81e2c692ed239023ecd.png)
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2024·山东·模拟预测
解题方法
2 . 如图①,将
个完全一样质量均匀长为
的长方体条状积木,一个叠一个,从桌子边缘往外延伸,最多能伸出桌缘多远而不掉下桌面呢?这就是著名的“里拉斜塔问题”.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/23/bc879c7d-8f43-4e6c-b6d8-ddd10ad2a335.png?resizew=507)
解决方案如下:如图②,若
,则当积木与桌缘垂直且积木重心
恰与桌缘齐平时,其伸出桌外部分最长为
,如图③,若
,欲使整体伸出桌缘最远,在保证所有积木最长棱与桌缘垂直的同时,可先将上面积木的重心与最下方的积木伸出桌外的最远端齐平,然后设最下方积木伸出桌外的长度为
,将最下方积木看成一个杠杆,将桌缘看成支点,由杠杆平衡原理可知,若积木恰好不掉下桌面,则上面积木的重力
乘以力臂
,等于最下方积木的重力
乘以力臂
,得出方程
,求出
.所以当叠放两个积木时,伸出桌外最远为
,此时将两个积木看成整体,其重心
恰与桌缘齐平.如图④,使前两块积木的中心
与下方的第三块积木伸出桌外的最远端齐平,便可求出
时积木伸出桌外的最远距离.依此方法,可求出4个、5个直至
个积木堆叠伸出桌外的最远距离.(参考数据:
,
为自然常数)
(1)分别求出
和
时,积木伸出桌外的最远距离.(用
表示);
(2)证明:当
时,积木伸出桌外最远超过
;
(3)证明:当
时,积木伸出桌外最远不超过
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c88d9142df6ba8e43c1a93bd04a1362.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/23/bc879c7d-8f43-4e6c-b6d8-ddd10ad2a335.png?resizew=507)
解决方案如下:如图②,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c87b351f16728b0023fd63678f8103c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23f919bd3dde10dbbc076f7ec5149699.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b00c12002fe4b07e3f91c7ae5c9192dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc2d3df37e73a8abea815f37dbb3fff5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc11468f07d42dda1d7d51107aab02fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18b4ed74387268c43450135937805101.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7050b91eacc62f73d872eeb628f3565c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2926c82d9ad9f5ba647c83fa3024f323.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c4f6f74444b2b7947fc6e35c8d62322.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c4f6f74444b2b7947fc6e35c8d62322.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be604061cf1591f7069472269d4c9719.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0af3a30b2f1dbc2fa12eb6759eee69d0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/041a7c8fc017f596542c5e6ec7d1c40b.png)
(1)分别求出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be604061cf1591f7069472269d4c9719.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fac3649308b528fd56545ba102dc42d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c88d9142df6ba8e43c1a93bd04a1362.png)
(2)证明:当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca71b6d6fd74f098d1e78161820dd3b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d916a406adac9fa4dcfbad152547ac9.png)
(3)证明:当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/30589b25ca71883ec4a5d1824c243bad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81731a804207d04115c15a16f3a27011.png)
您最近一年使用:0次
3 . 已知大气压强
(帕)随高度
(米)的变化满足关系式
是海平面大气压强.
(1)世界上有14座海拔8000米以上的高峰,喜马拉雅承包了10座,设在海拔4000米处的大气压强为
,求在海拔8000米处的大气压强(结果用
和
表示).
(2)我国陆地地势可划分为三级阶梯,其平均海拔如下表:
若用平均海拔的范围直接代表海拔的范围,设在第二级阶梯某处的压强为
,在第三级阶梯某处的压强为
,证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3eabd5f3a86afe49dcd70571e2b96cfd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3de17a73e40a55e7e930bbbec3de1d0.png)
(1)世界上有14座海拔8000米以上的高峰,喜马拉雅承包了10座,设在海拔4000米处的大气压强为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a886d45a46bdde67115c5911cb85ea6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3606c4a853a6a34cb7f33bea81b15a1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a886d45a46bdde67115c5911cb85ea6.png)
(2)我国陆地地势可划分为三级阶梯,其平均海拔如下表:
平均海拔(单位:米) | |
第一级阶梯 | ![]() |
第二级阶梯 | ![]() |
第三级阶梯 | ![]() |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adad9633b73dfbbb3d84b4f15979e99e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/845e602f8f75a107f186e4803ecafa05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02c0b5136e09293a4488211b80ba86ee.png)
您最近一年使用:0次
2023-07-29更新
|
124次组卷
|
2卷引用:辽宁省部分学校2022-2023学年高二下学期期末联考数学试题