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1 . (1)四点共圆是平面几何中一种重要的位置关系:
如图,
,
,
,
四点共圆,
为外接圆直径,
,
,
,求
与
的长度;
①(托勒密定理)任意凸四边形,两组对边的乘积之和不小于两条对角线的乘积,当且仅当该四边形的四个顶点共圆时等号成立.
②(婆罗摩笈多面积定理)若给定凸四边形的四条边长,当且仅当该四边形的四个顶点共圆时,四边形的面积最大.
根据上述材料,解决以下问题:
,
,
,
,求线段
长度的最大值;
(ii)见图2,若
,
,
,求四边形
面积取得最大值时角
的大小,并求出此时四边形
的面积.
如图,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a651eb577dbada1f29590e558d6f9fa2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ab5c45a72849d2cae1d65b282b5bd19.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
①(托勒密定理)任意凸四边形,两组对边的乘积之和不小于两条对角线的乘积,当且仅当该四边形的四个顶点共圆时等号成立.
②(婆罗摩笈多面积定理)若给定凸四边形的四条边长,当且仅当该四边形的四个顶点共圆时,四边形的面积最大.
根据上述材料,解决以下问题:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21ea52361458ce2e49ed0fe99d8e6c02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa7aeb2a8d1437eeb4482c3b6ad9f315.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/422f54faa21cdabc65b912b0e76eb68e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/212bfbd5575772ca36d6fc3e7b246e49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
(ii)见图2,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07160f14b3b453bebb64cb2bf96dc85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89c41757ae282475fb29ec1e8e02045d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
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解题方法
2 . 三角形的布洛卡点是法国数学家克洛尔于1816年首次发现.当
内一点
满足条件
时,则称点
为
的布洛卡点,角
为布洛卡角.如图,在
中,角
,
,
所对边长分别为
,
,
,记
的面积为
,点
为
的布洛卡点,其布洛卡角为![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa5301e013bcb05bbcce0ba5c8dfeb40.png)
.求证:
①
;
②
为等边三角形.
(2)若
求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec15e5cb6d4dc2cf6ba0bedd87514448.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa5301e013bcb05bbcce0ba5c8dfeb40.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d7b9d9bf0d5fc25c99170ab27fa4045.png)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fac4633c3e6bdc3426250ab4591e463.png)
②
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6492fa033f83d0775b049476612b86ec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ca890db371750d26ec7f049cfe4f714.png)
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3 . 英国物理学家牛顿在《流数法与无穷级数》一书中,给出了高次代数方程的一种数值解法—牛顿法.如图,具体做法如下:先在x轴找初始点
,然后作
在点
处的切线,切线与x轴交于点
,再作
在点
处的切线,切线与x轴交于点
,再作
在点
处的切线,以此类推,直到求得满足精度的近似解
为止.
已知
,在横坐标为
的点处作
的切线,切线与
轴交点的横坐标为
,继续牛顿法的操作得到数列
.
的通顶公式;
(2)若数列
的前
项和为
,且对任意的
,满足
,求整数
的最小值.
(参考数据:
,
,
,
)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9df2062940530232ab124a571e951ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/942c2141d01bde6b48210c56a17fc75e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d27c0ab3e2d7698f082854bafe4174dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fb652143b43cc9439a347b2b1dc5cf6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/942c2141d01bde6b48210c56a17fc75e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6cc47735cc385a3474bc1dabad322304.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/367304824e7eb354ffeb937fa209d80d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/942c2141d01bde6b48210c56a17fc75e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ec72ed76ec0fb772544a0c6ba0b88e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db1961eb75c093584f2b63763ef8fee9.png)
已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93eb7f6b803ac8e1e3b9def53134f966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87a60302649eb940748da818199e55da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aec19b68e3add9d5bfcc6269a1855b87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e976c0663fa749ca749f99842d21ca03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e976c0663fa749ca749f99842d21ca03.png)
(2)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4785ee9337c71c6618aa974c6bb9a21a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f093c61867ee4ce75f951d46b9b123.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e854662d424309991f86678df32fb0c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
(参考数据:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3bf7c943a75895140801523c1184ed8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/539ae63efa6aab52e5b6a4190c684ab9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17e3b17aa93b9ff98c93f7d097b8c38d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41a5e288e8c07edfb9ad3c5f0f322fcc.png)
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4 . 在概率统计中,常常用频率估计概率.已知袋中有若干个红球和白球,有放回地随机摸球
次,红球出现
次.假设每次摸出红球的概率为
,根据频率估计概率的思想,则每次摸出红球的概率
的估计值为
.
(1)若袋中这两种颜色球的个数之比为
,不知道哪种颜色的球多.有放回地随机摸取3个球,设摸出的球为红球的次数为
,则
.
(注:
表示当每次摸出红球的概率为
时,摸出红球次数为
的概率)
(ⅰ)完成下表,并写出计算过程;
(ⅱ)在统计理论中,把使得
的取值达到最大时的
,作为
的估计值,记为
,请写出
的值.
(2)把(1)中“使得
的取值达到最大时的
作为
的估计值
”的思想称为最大似然原理.基于最大似然原理的最大似然参数估计方法称为最大似然估计.具体步骤:先对参数
构建对数似然函数
,再对其关于参数
求导,得到似然方程
,最后求解参数
的估计值.已知
的参数
的对数似然函数为
,其中
.求参数
的估计值,并且说明频率估计概率的合理性.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/613f6de938db4bb3a7f98226d3a4c793.png)
(1)若袋中这两种颜色球的个数之比为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc5881f1ce9b4172ca346032d0fd1e3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a829fdd8ec0f3b7ede883cf2c3e53b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fadbd1d2d0294d04834dde31e0e4caaf.png)
(注:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c74de541a96a252ca6b4bf05381a03ec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
(ⅰ)完成下表,并写出计算过程;
0 | 1 | 2 | 3 | |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c74de541a96a252ca6b4bf05381a03ec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0cf2e58249dd993ae42a7bd6d9ba0005.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0cf2e58249dd993ae42a7bd6d9ba0005.png)
(2)把(1)中“使得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c74de541a96a252ca6b4bf05381a03ec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0cf2e58249dd993ae42a7bd6d9ba0005.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0807dbbfdeeaeffd987c4de037b892f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acb13cf58c2aa7591391cfa8d515dc64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b1aecbef5ad07da9949972dbcb9d659.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c21d19789d426d0ed871d45ac6175f66.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/889b80977780bb8caec3c90954b91a21.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
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2024-06-04更新
|
150次组卷
|
6卷引用:山东省青岛第一中学2023-2024学年高二下学期第一次模块考试数学试题
解题方法
5 . 法国著名军事家拿破仑·波拿巴最早提出的一个几何定理:“以任意三角形的三条边为边向外构造三个等边三角形,则这三个等边三角形的外接圆圆心恰为等边三角形的顶点”.在
中,内角
的对边分别为
,且
,以
,
为边向外作三个等边三角形,其外接圆圆心依次为
.若
,
的面积为
,求
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b28493133d5e7cbbfa6a63bfecab966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cca04b2a2b61d62a809776670a60c09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9fd4dfee3258dc4e386330bac4ef0f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e65397f11ea8af736f38debadf420c4a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7736a0467e1127dc3963098e148ca64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/131739cb68310e0742befae171a2d47e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
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解题方法
6 . 记
上的可导函数
的导函数为
,满足
的数列
称为函数
的“牛顿数列”.已知数列
为函数
的牛顿数列,且数列
满足
.
(1)证明数列
是等比数列并求
;
(2)设数列
的前
项和为
,若不等式
对任意的
恒成立,求t的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a43b2faa4f81f32d94612dce724e772b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/724340d69477c0ec2418c392b22b1cab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d11e3e7cd27440bbc6a93856c997b8d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e976c0663fa749ca749f99842d21ca03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e976c0663fa749ca749f99842d21ca03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff2b53cd9892f6d174509740afbc69d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da8765813233a2c419d2d3bbc56f6670.png)
(1)证明数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
(2)设数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e3d2f5b3ed3ee8ecce9a586f07244e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e97769855336d73371930df1f187875e.png)
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解题方法
7 . 费马点是在三角形中到三个顶点距离之和最小的点.具体位置取决于三角形的形状,如果三角形的三个内角均小于
,费马点是三角形内部对三边张角均为
的点;如果三角形有一个内角大于或等于
,费马点就是该内角所在的顶点.
已知△ABC中,角A,B,C所对的边分别为a,b,c,O为费马点.
(1)若
,
,
,求
的值;
(2)若
,
,求
的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c0927afc571a7c966c98192040979e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c0927afc571a7c966c98192040979e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c0927afc571a7c966c98192040979e.png)
已知△ABC中,角A,B,C所对的边分别为a,b,c,O为费马点.
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/783d6adfa8fb1352679c5185258d842a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a3c442579603164f3fc19458677d307.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcb5bac75f36bb1dc5c8190d4dbe681d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/569b5df7e2e4642091364efefe8dddf9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b550ee821ee1838384835e81fc34b67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa1466856bf2570685d3629c1f813748.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c2bd0a04afc05de0f6a86ada42411f2.png)
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8 . 欧拉公式:
(
为虚数单位,
),是由瑞士著名数学家欧拉发现的.它将指数函数的定义域扩大到了复数,建立了三角函数和指数函数之间的关系,它被誉为“数学中的天桥”.
(1)根据欧拉公式计算
;
(2)设函数
,求函数
在
上的值域.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fdc0ab4d45a4bef21ba8ae793f2e76f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a7035cd4adda5d72a9fc9f9fda75995.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb63478132d4c1fef3c17e591919da83.png)
(1)根据欧拉公式计算
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9ac408521487ac9928cdf11755123f2.png)
(2)设函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88007d2f3f8ba2f04fa067bcac670459.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d275fbb3ee5cd1177ca5a2ceecbbef0f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4f22e10962fef7ee009160976c748578.png)
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9 . 十七世纪法国数学家、被誉为业余数学家之王的皮埃尔·德·费马提出的一个著名的几何问题:“已知一个三角形,求作一点,使其与这个三角形的三个顶点的距离之和最小.”它的答案是:“当三角形的三个角均小于
时,所求的点为三角形的正等角中心,即该点与三角形的三个顶点的连线两两成角
;当三角形有一内角大于或等于
时,所求点为三角形最大内角的顶点.”在费马问题中所求的点称为费马点. 试用以上知识解决下面问题:已知
的内角
所对的边分别为
,且![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40ec9cff8627e76b61e6474e57d7a7ef.png)
(1)求
;
(2)若
,设点
为
的费马点,求
;
(3)设点
为
的费马点,
,求实数
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c0927afc571a7c966c98192040979e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c0927afc571a7c966c98192040979e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c0927afc571a7c966c98192040979e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40ec9cff8627e76b61e6474e57d7a7ef.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44ac38c5cc951497a4a37778b191bcce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b8f8a1e38db0e55b9b1934569b24e74.png)
(3)设点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b01862dfc85d45102a1343c36cb6dfe5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
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10 . 阅读材料:材料一:我国南宋的数学家秦九韶在《数书九章》中提出了“三斜求积术”:若把三角形的三条边分别称为小斜、中斜和大斜,记小斜为
,中斜为
,大斜为
,则三角形的面积为
.这个公式称之为秦九韶公式;材料二:古希腊数学家海伦在其所著的《度量论》或称《测地术》中给出了用三角形的三条边长表示三角形的面积的公式,即已知三角形的三条边长分别为
,则它的面积为
,其中
,这个公式称之为海伦公式;请你结合阅读材料解答下面的问题:
(1)证明秦九韶公式与海伦公式的等价性;
(2)已知
的面积为24,其内切圆半径为
,求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7110e0e86c475f567894796807a21cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/684c13a2cea962fb204256ca433a4d58.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/71d788614f1841b4943b30fe6fd1eff3.png)
(1)证明秦九韶公式与海伦公式的等价性;
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc3c42cefcf156e774c03e1e3626c04b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69225cfdfbc0a9a1ccfdd15c46353b8f.png)
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