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)
您最近一年使用:0次