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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2 . 已知函数
,则下列说法正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3cc2f69d2d3d82f6a055892a6437965c.png)
A.函数![]() ![]() |
B.函数![]() ![]() |
C.将函数![]() ![]() ![]() ![]() ![]() ![]() |
D.若![]() ![]() ![]() ![]() |
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3 . 已知数列
的前n项和为
,且满足
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/234605545a58197b26d52799abbb17b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06fbdd2e3efbef1ff014df55b242eced.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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名校
解题方法
4 . 已知正数m,n满足
,则
的最大值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49f0974ecbf06e833e087063db169001.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8fd1f0ace9ca0b79929e73af6c201c2e.png)
A.5 | B.6 | C.7 | D.8 |
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5 . 已知a,b,c为三条不同的直线,
为两个不同的平面,则下列说法正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4e288596fa3811dd2c17bded60e82e7.png)
A.若![]() ![]() |
B.若![]() ![]() |
C.若![]() ![]() |
D.若![]() ![]() |
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6 . 已知抛物线
的焦点为F,O为原点,直线
与该抛物线交于M,N两点,且
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10f4123c19136d3a4dc040dce8e34e14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/254d0e3be93b3a32e45f3cd1f8c44891.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c0b06dc01c30d13f64be2ac6a1d811e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3bb697312c620b91375b3a01f37ac00b.png)
A.12 | B.13 | C.14 | D.15 |
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解题方法
7 . 已知点
分别为椭圆
的左、右焦点,过
的直线l(斜率不为0)交椭圆C于P,Q两点,当直线l的斜率不存在时,
.
(1)求椭圆C的离心率;
(2)若点A,B分别为椭圆C的左、右顶点,且
面积的最大值为
,直线
与直线
相交于点M,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d2a97987f71835f519b462f5b8f5957.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad523e69a1bf925e73a22900b9855df2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6dc791ae552024ea0df7905bf190f30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/320c0dd8f44d5c72757b1ad1318800d6.png)
(1)求椭圆C的离心率;
(2)若点A,B分别为椭圆C的左、右顶点,且
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2205cffebf8c4d5f81d15ed7b85c8936.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38387ba1cadfd3dfc4dea4ca9f613cea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf702adb116c1e46569eb7050d029f49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c3d833dad7bda8887fdfcaf00bb4c49.png)
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解题方法
8 . 如图,在三棱锥
中,
是边长为2的等边三角形,且平面
平面
.
体积的最大值;
(2)若
,点E为线段
上一点,当二面角
为
时,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f910a9be78a6580195c0c51d6259a5c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcf6dc837ae85207789b94d109c5c2eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5d3866a226333dbb75754ec9ab916fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/324d453870b345da0c41977290192f94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be6a6301878fed2a01413020b27310a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a50b31b40c0d28bed4572ce27b30a19.png)
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9 . 在
中,内角A,B,C的对边分别为a,b,c,点D为边
上一点,且满足
.
(1)证明:
;
(2)若
为内角A的平分线,且
,求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccbb66c477a0b0ab67e5759b72c3c802.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c52b857c7ca55dfa6da108df1d3cee2.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e828b8edf7a8f2cdcfceb13a4e05bf6e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79b01adc561735ff5be9bb97266918f2.png)
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10 . 圆
与圆
的公切线的方程为__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd83d733037f9c4305f4e3a7f5bbe142.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45e7abf8f29e5b328f3090171da09724.png)
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