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1 . 城市住宅小区的绿化建设是提升小区品质、改善空气质量、创造美丽怡人的居住环境的重要组成部分.如图1,长沙市某小区居民决定在小区内部一块半径长为
的半圆形荒地上建设一块矩形绿化园
,其中
位于半圆
的直径上,
位于半圆
的圆弧上,记
.
面积
关于
的函数解析式,并求该矩形面积的最大值以及取得最大值时
的值.
(2)部分居民提出意见,认为这样的绿化同建设太过单调,一名居住在本小区的设计师提出了如图2的绿化园建设新方案:在半圆
的圆弧上取两点
,使得
,扇形区域
和
均进行绿化建设,同时,在扇形
内,再将矩形区域
也全部进行绿化建设,其中
分别在直线
上,
与
平行,
在扇形
的圆弧上,请问:与(1)中的原方案相比,选择哪一种方案所得到的绿化面积的最大值更大?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c08094f72d5bd69246c453dd28e33d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b32c05247f6998d7a70d31d13be4148c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39acab3cfb59bfc9591371721ab01d93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d39091bc47dd9256d9aa12fbb036647.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b32c05247f6998d7a70d31d13be4148c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
(2)部分居民提出意见,认为这样的绿化同建设太过单调,一名居住在本小区的设计师提出了如图2的绿化园建设新方案:在半圆
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7789a500686c7a73770404ead6af0590.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3163dec1ebad172d77df3d1eba90fd9e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/945d27bb4d47e78d472186cb02314a8b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ad54f888ceafaf28543a2b9ceab5731.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1eb76f88cb973c220cffa1c9c0721a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7b92a95f86be61b826727d2bfef9dc1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c0f067a2a348ceb24a408f82992eab8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f65dbed884e2248ec075655c684aa7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e42887d9bf31c1dd99f13c39e63c9ab9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6bce3d91ca23b86d8c6625f2632e437.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1eb76f88cb973c220cffa1c9c0721a6.png)
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2 . 如图,在梯形
中,
,
,
,
,
在线段
上.
,用向量
,
表示
,
;
(2)若AE与BD交于点F,
,
,
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10df84d553a8826a7ce9bff4bf0d95b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54275b7e571660d0a9e0370fbfe5050b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55c24a968c73e960698a572ab01e3698.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/267ace52b64e1e7dfc5211e033255b7d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4148817c0a463417ec02769a7abc5913.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abcb5d89b04570ceda2c29e11cb27a57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/304a7f07db2ec637baadf8f0ab91c85c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a34bf00aeba15bce2cdee8ab487388dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d021a5c98388463d577675e58068aa7.png)
(2)若AE与BD交于点F,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1eb6b6ee8c74422693cc91262d54070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f673c9b0ad6537149f4d9b3b6d8c63c4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c7062eabb42603c793fef3a792a9191.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
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2024-05-23更新
|
391次组卷
|
3卷引用:湖南省岳阳县第一中学、汨罗市第一中学2023-2024学年高一下学期五月联考数学试题
名校
解题方法
3 . 二项分布是离散型随机变量重要的概率模型,在生活中被广泛应用.现在我们来研究二项分布的简单性质,若随机变量
.
(1)证明:(ⅰ)
(
,且
),其中
为组合数;
(ⅱ)随机变量
的数学期望
;
(2)一盒中有形状大小相同的4个白球和3个黑球,每次从中摸出一个球且不放回,直到摸到黑球为止,记事件A表示第二次摸球时首次摸到黑球,若将上述试验重复进行10次,记随机变量
表示事件A发生的次数,试探求
的值与随机变量
最有可能发生次数的大小关系.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/870528aa6be6f56bae0eb6b10a765c02.png)
(1)证明:(ⅰ)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f7ea00923d9f3ccadd6d6186993836a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9ef0a61e3c701a7cb3a9f9ca3c8dd37.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53b4b3879d1c6debf0333008f686634e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fdea830c734212c9831f428918636e8.png)
(ⅱ)随机变量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2bc4bd923f697154764599eb542e9d96.png)
(2)一盒中有形状大小相同的4个白球和3个黑球,每次从中摸出一个球且不放回,直到摸到黑球为止,记事件A表示第二次摸球时首次摸到黑球,若将上述试验重复进行10次,记随机变量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a829fdd8ec0f3b7ede883cf2c3e53b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/71701db4b413f2364dbcbd612fbc8a67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a829fdd8ec0f3b7ede883cf2c3e53b.png)
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解题方法
4 . 对于椭圆
,令
,
,那么在坐标系
中,椭圆经伸缩变换得到了单位圆
,在这样的伸缩变换中,有些几何关系保持不变,例如点、直线、曲线的位置关系以及点分线段的比等等;而有些几何量则等比例变化,例如任何封闭图形在变换后的面积变为原先的
,由此我们可以借助圆的几何性质处理一些椭圆的问题.
(1)在原坐标系中斜率为k的直线l,经过
,
的伸缩变换后斜率变为
,求k与
满足的关系;
(2)设动点P在椭圆
上,过点P作椭圆
的切线,与椭圆
交于点Q,R,再过点Q,R分别作椭圆
的切线交于点S,求点S的轨迹方程;
(3)点
)在椭圆
上,求椭圆上点B,C的坐标,使得△ABC的面积取最大值,并求出该最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8429aec72d26401b12a55b8337261df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/070cb835e194f9bb99aba9daf58bd2b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50443405ab95a95149c68f59f96619de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/863b5f9f0a7c6b7956979a5abc76d8d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e08c4a230e32f550374a5fa4db5f204.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/848d4055ca831ecde46d1b666ba9e33d.png)
(1)在原坐标系中斜率为k的直线l,经过
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/070cb835e194f9bb99aba9daf58bd2b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50443405ab95a95149c68f59f96619de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fbc8ced3660dab6e343773fd9dccebc3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fbc8ced3660dab6e343773fd9dccebc3.png)
(2)设动点P在椭圆
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/841307fdcdbbccacd07b652db535631f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce30fc0664cca88dbe6d38f32aee81e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd76519af3c3a098a590ad302acc003b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aaafb050b24c4e806c480e0665aaa5a.png)
(3)点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad492d5033448d419df9c9b75a71894e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/271e595c257e4c0ade90a9bbbf0e6b0d.png)
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5 . 如图为英国生物学家高尔顿设计的“高尔顿板”示意图,每一个黑点代表钉在板上的一颗钉子,下方有从左至右依次编号为
的格子(此时钉子层数为
).当小球从板口下落时,它将碰到钉子并有
的概率向左或向右滚下,继续碰至下一层钓子,依次类推落入底部格子.记小球落入格子的编号为
.定义
.
时
的分布列;
(2)证明:
;
(3)改变格子个数(钉子层数相应改变),进行
次实验,第
且
次实验中向格子最大编号为
的高尔顿板中投入
个小球,记所有实验中所有小球落入的格子编号之和为
.已知无交集的独立事件的期望具有累加性,设每次实验、每次投球相互独立,求
关于
的表达式.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc67b26dd6f40e0630602168cbc3d784.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63c2fcac14983abc2b2429936fe0fbb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4f1e3925bda80e8223bf7e431585847.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be604061cf1591f7069472269d4c9719.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc5fbb0a0595b5a0153c8b570a6473a0.png)
(3)改变格子个数(钉子层数相应改变),进行
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6bd9b00a78632a5355fe47b418996ad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6efe3b837da0d468d85060c9e0e3b639.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/690dd59ae66def0cb99f5bcd3d515e82.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e77d6f15137ae5d98b0d546672b6f68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a829fdd8ec0f3b7ede883cf2c3e53b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b0bd6753e573bfbe6742d08ef6dfe83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
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6 . 函数的凹凸性的定义是由丹麦著名的数学家兼工程师Johan Jensen在1905年提出来的.其中对于凸函数的定义如下:设连续函数
的定义域为
(或开区间
或
,或
都可以),若对于区间
上任意两个数
,均有
成立,则称
为区间
上的凸函数.容易证明譬如
都是凸函数.Johan Jensen在1906年将上述不等式推广到了
个变量的情形,即著名的Jensen不等式:若函数
为其定义域上的凸函数,则对其定义域内任意
个数
,均有
成立,当且仅当
时等号成立.
(1)若函数
为
上的凸函数,求
的取值范围:
(2)在
中,求
的最小值;
(3)若连续函数
的定义域和值域都是
,且对于任意
均满足下述两个不等式:
,证明:函数
为
上的凸函数.(注:
)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4776c85b79df196f606d3ebf3697fbc3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4562f3225c98cf5cb11b47d98c9cc9c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4b3dce3b2dd078fdd6b4cfd301927f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b0c0214295e38221c4e98d13a8b6b37.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4776c85b79df196f606d3ebf3697fbc3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ce7ae90d808f05e86ea063238e4b2f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1bedaf3854b48806b82b3b804451cf8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4776c85b79df196f606d3ebf3697fbc3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb2d0d76b383beb0f422ed02a2b888b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c83590c4a7ea5636843dd4b60c67cb40.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ae7a1a59fbb460ff17c32dc7e3bb4ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73223617c8855826298d435673787a94.png)
(1)若函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9165c6db50a97f8ed52b759e57ba2644.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a43b2faa4f81f32d94612dce724e772b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
(2)在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82822f0c261ac2193ef264fe68321833.png)
(3)若连续函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be1ce3f01e2b6364f9a9fdaf197d5e29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/870ebc2f7aabb028024894568d749934.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea9484fcea82180e9886a18d7a947b03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/963c40a0a3722b8f432ee37eef7cb1a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa06f4df6281bd147ce5bd8332cfb66e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/870ebc2f7aabb028024894568d749934.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e56b9605ab2765c9811e9432e38d905e.png)
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解题方法
7 . 已知正四面体的棱长为3,
,
,过点
作直线分别交
,
于
,
.设
,
(
).
的最小值及相应的
,
的值;
(2)在(1)的条件下,求:
①
的面积;
②四面体
的内切球的半径.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/714fe049aea26e4275f2389206b630fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab5777c7eb5f6e1d4b800f3ad7f08d75.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9abaeba15f3abdd877bc701af52c5cd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1bd1adfe4cc6566218f19970c2fd3b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13a7a2f33d8bced8ab9010b7e8ca582f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/75a7fecf55c00d2cd1358e8daaa85a3b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/496c777ba1fd4ba09fed8d5892461486.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1d6a99033826bd1b44f58b9e11ff52e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1100379a4385b9ce064847bc21760adc.png)
(2)在(1)的条件下,求:
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/999c42a021bdc576f097246b9e64d986.png)
②四面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e453d251928fc8058ceeee602874702.png)
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2024-05-08更新
|
488次组卷
|
2卷引用:湖南省常德市汉寿县第一中学2023-2024学年高一下学期4月期中考试数学试题
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解题方法
8 . 京剧被誉为中国文化的瑰宝.每个脸谱都有其独特的象征意义,是京剧中不可或缺的一个组成部分.某商店售卖的京剧脸谱娃娃共有三种款式,有直接购买和盲盒购买两种方式.若直接购买京剧脸谱娃娃,则每个京剧脸谱娃娃售价54元,可选定款式;若盲盒购买京剧脸谱娃娃,则每个盲盒售价27元,盲盒中的一款京剧脸谱娃娃是随机的.
(1)甲采用盲盒购买的方式,每次购买一个盲盒并打开,若买到的京剧脸谱娃娃中出现相同款式,则停止购买.用
表示甲购买盲盒的个数,求
的分布列.
(2)乙计划收集一套京剧脸谱娃娃(三种款式各一个),先购买盲盒,每次购买一个盲盒并打开(乙最多购买3个盲盒),若未集齐一套京剧脸谱娃娃,再直接购买没买到的款式,以购买费用的期望值为决策依据,问乙应购买多少个盲盒?
(1)甲采用盲盒购买的方式,每次购买一个盲盒并打开,若买到的京剧脸谱娃娃中出现相同款式,则停止购买.用
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
(2)乙计划收集一套京剧脸谱娃娃(三种款式各一个),先购买盲盒,每次购买一个盲盒并打开(乙最多购买3个盲盒),若未集齐一套京剧脸谱娃娃,再直接购买没买到的款式,以购买费用的期望值为决策依据,问乙应购买多少个盲盒?
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2024-05-08更新
|
494次组卷
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3卷引用:湖南省长沙市第一中学、长沙市一中城南中学等多校2023-2024学年高二下学期期中考试数学试题
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解题方法
9 . 在平面直角坐标系
中,直线
交椭圆
于
两点,点
关于
轴的对称点为
.
(1)用含
的式子表示
的中点坐标;
(2)证明:直线
过定点.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ee31829d0d4d5f779a957d7df8058ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e3cc60d53da732d35fb070e71a97826.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e0b4bbfa0ed04cd3c2454d99d64e29c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6bce3d91ca23b86d8c6625f2632e437.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2708fa6298e52f617383efc175b71ddc.png)
(1)用含
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a5f1641947153c80b987320885a2b57.png)
(2)证明:直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea68142955809f9f40b15e3fa0f5bdd5.png)
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名校
10 . 折纸是一项玩法多样的活动.通过折叠纸张,可以创造出各种各样的形状和模型,如动物、花卉、船只等.折纸不仅是一种艺术形式,还蕴含了丰富的数学知识.在纸片
中,A,B,C所对的边分别为a,b,c,
的面积为
,
.
(1)证明:
.
(2)若
,求
的值.
(3)在(2)的条件下,若
,D是AB的中点,现需要对纸片
做一次折叠,使C点与D点重合,求折叠后纸片重叠部分的面积
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e097c8d4c948de063796bd19f85b3a9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1225fd03e8e8730dac8487dae5387635.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e482cb92791ee3dc96e0a086e46cc23f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b30dc055367efbff99618485781eeb7d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5201fc26d013f6fb889933c0e32f5c53.png)
(3)在(2)的条件下,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5742b2684d00be50a66e01c9acb6b51f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e0bd63f55069a3bc870915010b39225.png)
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