解题方法
1 . “费马点”是由十七世纪法国数学家费马提出并征解的一个问题,该问题是:“在一个三角形内求作一点,使其与此三角形的三个顶点的距离之和最小”.如图1,三个内角都小于
的
内部有一点
,连接
,求
的最小值.我们称三角形内到三角形三个顶点距离之和最小的点为费马点.要解决这个问题,首先应想办法将这三条端点重合于一点的线段分离,然后再将它们连接成一条折线,并让折线的两个端点为定点,这样依据“两点之间,线段最短”,就可求出这三条线段和的最小值.某数学研究小组先后尝试了翻折、旋转、平移的方法,发现通过旋转可以解决这个问题,具体的做法如图2,将
绕点
顺时针旋转
,得到
,连接
,则
的长即为所求,此时与三个顶点连线恰好三等分费马点
的周角.同时小组成员研究教材发现:已知对任意平面向量
,把
绕其起点沿逆时针方向旋转
角得到向量
.
,把点
绕点
沿顺时针方向旋转
后得到点
,求点
的坐标;
(2)在
中,
,借助研究成果,直接写出
的最小值;
(3)已知点
,求
的费马点
的坐标.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/231b861d6d1f1d0b9f52b041cb40eb62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
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(2)在
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7ed53a398b1d6b7b4abbb43a9abcf1f.png)
(3)已知点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24a65f35281b21fdfaf7c437fbd321eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
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解题方法
2 . 降维类比和升维类比主要应用于立体几何的学习,将空间三维问题降为平面二维或者直线一维问题就是降维类比.平面几何中多边形的外接圆,即找到一点,使得它到多边形各个顶点的距离相等.这个点就是外接圆的圆心,距离就是外接圆的半径.若这样的点存在,则这个多边形有外接圆,若这样的点不存在,则这个多边形没有外接圆.事实上我们知道,三角形一定有外接圆,如果只求外接圆的半径,我们可通过正弦定理来求,我们也可以关注九年义教初中《几何》第三册第94页例2.的结论:三角形外接圆的直径等于两边的乘积除以第三边上的高所得的商.借助求三角形外接圆的方法解决问题:若等腰梯形
的上下底边长分别为6和8,高为1,这个等腰梯形的外接圆半径为__________ ;轴截面是旋转体的重要载体,圆台的轴截面中包含了旋转体中的所有元素:高、母线长、底面圆的半径,通过研究其轴截面,可将空间问题转化为平面问题.观察图象,通过类比,我们可以找到一般圆台的外接球问题的研究方法,正棱台可以看作由圆台切割得到.研究问题:如图,正三棱台的高为1,上、下底面边长分别为
和
,其顶点都在同一球面上,则该球的体积为__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adbd3e8cf8325999cde03adf845d3dd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41322821ce31416fdac8dd6e0aa41c71.png)
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3 . 利普希兹条件是数学中一个关于函数光滑性的重要概念,设
定义在
上的函数,若对于
中任意两点
,都有
,则称
是“
-利普希兹条件函数”.
(1)判断函数
,
在
上是否为“1-利普希兹条件函数”;
(2)若函数
是“
-利普希兹条件函数”,求
的最小值;
(3)设
,若存在
,使
是“2024-利普希兹条件函数”,且关于
的方程
在
上有两个不相等实根,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f030c36bb8786df88d401792062a4100.png)
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(1)判断函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ab466aedd6e176088d8dee7bc3e3aaa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/344ccbf79da6ad7e3709d6fa72efb756.png)
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(2)若函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44edb8cc6555fc6ec8d0bfd7d5b33f0a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
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(3)设
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
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4 . 如图所示,圆柱
的底面半径为
,
,
为圆
的直径,点
为圆
上的动点,点
为圆柱侧面上的动点(不含边界),
平面
,则
的取值范围为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e65ac334119ccd6204402a7aba29a55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d599cb4a589f90b0205f24c2e1fa021e.png)
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A.![]() | B.![]() |
C.![]() | D.![]() |
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5 . 某学校的数学节活动中,其中有一项“抽幸运数字”擂台游戏,分甲乙双方,游戏开始时,甲方有2张互不相同的牌,乙方有3张互不相同的牌,其中的2张牌与甲方的牌相同,剩下一张为“幸运数字牌”.游戏规则为:
①双方交替从对方抽取一张牌,甲方先从乙方中抽取;
②若抽到对方的牌与自己的某张牌一致,则将这两张牌丢弃;
③最后剩一张牌(幸运数字牌)时,持有幸运数字牌的那方获胜.
假设每一次从对方抽到任一张牌的概率都相同.奖励规则为:若甲方胜可获得200积分,乙方胜可获得100积分.
(1)已知某一轮游戏中,乙最终获胜,记
为甲乙两方抽牌次数之和.
(ⅰ)求
;
(ⅱ)求
,
;
(2)为使获得积分的期望最大,你会选择哪一方进行游戏?并说明理由.
①双方交替从对方抽取一张牌,甲方先从乙方中抽取;
②若抽到对方的牌与自己的某张牌一致,则将这两张牌丢弃;
③最后剩一张牌(幸运数字牌)时,持有幸运数字牌的那方获胜.
假设每一次从对方抽到任一张牌的概率都相同.奖励规则为:若甲方胜可获得200积分,乙方胜可获得100积分.
(1)已知某一轮游戏中,乙最终获胜,记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
(ⅰ)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ef5ccb0e7b118785332d753891a2679.png)
(ⅱ)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/302b1c2054e8f0993b86addead6b2f79.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9cb7258cff29fdc988476f2087e7103.png)
(2)为使获得积分的期望最大,你会选择哪一方进行游戏?并说明理由.
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解题方法
6 . 如图,已知梯形
中,
,
,点
,
分别为线段
,
上的动点,
,点
为线段
中点,则以下说法正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f79863ffcfa63117ca6741b20a48e69.png)
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A.若![]() ![]() | B.![]() |
C.![]() | D.若![]() ![]() ![]() |
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名校
解题方法
7 . 已知数列
的前
项和为
,若存在常数
,使得
对任意
都成立,则称数列
具有性质
.
(1)若数列
为等差数列,且
,求证:数列
具有性质
;
(2)设数列
的各项均为正数,且
具有性质
.
①若数列
是公比为
的等比数列,且
,求
的值;
②求
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ee7ed704a954d0414be6c3148bd566d.png)
(1)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/193a0efaa1aa835eb3e061bb25dad4dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7470297de40027847c5c73fc5d1719c.png)
(2)设数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ee7ed704a954d0414be6c3148bd566d.png)
①若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa8a716a31b0f51b70fdf9bdb257909.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4338dd5d6ac02dbb9d5069eb98f436d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa8a716a31b0f51b70fdf9bdb257909.png)
②求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
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7日内更新
|
241次组卷
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4卷引用:高二下期末考前押题卷01--高二期末考点大串讲(人教B版2019选择性必修)
(已下线)高二下期末考前押题卷01--高二期末考点大串讲(人教B版2019选择性必修)河南师范大学附属中学2024届高三下学期最后一卷数学试题江西省临川第二中学2023-2024学年高二下学期6月月考数学试题江苏省泰州市2024届高三下学期四模数学试题
名校
解题方法
8 . 设离散型随机变量X,Y的取值分别为
,
.定义X关于事件“
”
的条件数学期望为
,已知条件数学期望满足全期望公式
.解决如下问题:为了研究某药物对于微生物A生存状况的影响,某实验室计划进行生物实验.在第1天上午,实验人员向培养皿中加入10个A的个体.从第1天开始,实验人员在每天下午向培养皿中加入该种药物.当加入药物时,A的每个个体立即产生1次如下的生理反应(设A的每个个体在当天的其他时刻均不发生变化,不同个体的生理反应相互独立):①直接死亡;②分裂为2个个体,且这两种生理反应是等可能的.
设第n天上午培养皿中A的个体数量为
.规定
,
.
(1)求
,
;
(2)证明
;
(3)已知
,求
,并结合(2)说明其实际含义.
附:对于随机变量X,
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4c5ef7cc433f6d83d5dace3007d81e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12044571bb321a077e62fe3d24921d2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dfe778b3e0bbd2220de99c382ec323b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d94932ae5d8a1772b36b5268a234a046.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8baaca444be2d6b341f0310d17ba5558.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7af49ca40f22b61efbda45d7632da572.png)
设第n天上午培养皿中A的个体数量为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93d0f3799612b81e85b87241ec8eee68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f93ddfb6148d7377a0d659b2429706a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/843b0b9191cabb7c63a406e37650a96a.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f7af337627e78cece1daf3a8cf11a2a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a6c7173930e7a13eb63e18f901f7772.png)
(2)证明
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09d6030f60e25c6344f62d900167a604.png)
(3)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8218c7894f6caad3396a4eab9e6094a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58664d4fcfe5b765ccc1f86d7c29ce1c.png)
附:对于随机变量X,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c83507976fbfb5685fd79058bc438f0a.png)
您最近一年使用:0次
2024-06-17更新
|
217次组卷
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2卷引用:湖北省黄冈市浠水县第一中学2023-2024学年高二下学期期末质量检测数学试题
9 . 已知向量
,
,定义运算
,同时定义
.
(1)若
,求实数
的取值集合;
(2)已知
,求
;
(3)已知定义域为
的函数
满足
为奇函数,
为偶函数,且
时,
,是否存在实数
,使
?若存在,求出
的值;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7ec6dba44a83ae69146c26a2eec325c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66717aa3e7a771427c1d4433c77a5e29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4817c9821c3c5268e665a3ebcfe2e9cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/153f8261059b286d175e53adb666d0bd.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e993a236a70e4a094013a28c07079f84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/237b1a6f3e6ee0ef92b4aef7bffe58ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b5285f8cfbab2baf73267d7649a58ac.png)
(3)已知定义域为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a43b2faa4f81f32d94612dce724e772b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0eb7df298a9364b36e079a61caec815c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91340ce6d32493c33527a32c2d448896.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ffde73ff7d3cd5125eb8d8a17a9f01c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/994dcf841d356002fcebaed37497013c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de03de9f4bea859252f0158b32acf378.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2bb0b435b3f1a00ee1df0d02384d6e57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
您最近一年使用:0次
名校
10 . 已知函数
,则下列说法正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93208bc770714ae8311ab2ba6274ea8d.png)
A.存在![]() ![]() ![]() |
B.对任意![]() ![]() ![]() |
C.对任意![]() ![]() ![]() |
D.存在![]() ![]() ![]() |
您最近一年使用:0次
2024-06-16更新
|
345次组卷
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6卷引用:内蒙古名校联盟2023-2024学年高二下学期教学质量检测数学试题