1 . 甲烷是一种有机化合物,分子式是
,它作为燃料广泛应用与民用和工业中,近年来科学家通过观测数据,证明了甲烷会导致地球表面温室效应不断增加,深入研究甲烷,趋利避害,成为科学家面临的新课题,甲烷分子的结构为正四面体结构,四个氢原子位于正四面体的四个顶点,碳原子位于正四面体的中心,碳原子和氢原子之间形成的四个碳氢键的键长相同,键角相等,请你用学过的数学知识计算甲烷碳氢键之间的夹角余弦值______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eff19349a80467d65564cc2953f0c978.png)
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2 . 已知
是
所在平面内一点,以下说法正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
A.若动点![]() ![]() ![]() ![]() |
B.若点![]() ![]() ![]() ![]() |
C.若![]() ![]() ![]() ![]() ![]() |
D.若![]() ![]() ![]() |
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5卷引用:福建省福州格致中学2020-2021学年高一下学期期中考数学试题
福建省福州格致中学2020-2021学年高一下学期期中考数学试题重庆市开州中学2021-2022学年高一下学期第一次阶段性考试数学试题江苏省盐城市阜宁县(部分校)2023-2024学年高一下学期期中考试数学试题(A卷)(已下线)第八章 向量专练5—四心问题-2022届高三数学一轮复习(已下线)专题9-2 轨迹八类求法-2022年高考数学毕业班二轮热点题型归纳与变式演练(全国通用)
名校
解题方法
3 .
中,角
,
,
满足
,且
.
(1)在
边上有一点
,且
,若
,求
;
(2)求
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e428e7a09732be85c1224e9c8f6a71c5.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/ffdb2c5f6e426cd3a0243cc6a6bd7512.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f8eeeea1c9652cacce976f8129cf520.png)
(1)在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e735a28578ba191da6d4f3b0f8e8729.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/714cc3707bba3bfdb56e251999be8592.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3d08f0ab6e573253450e03427e13db1.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6cd00662d7395918fac8794d85ee13a5.png)
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3卷引用:重庆市万州第二高级中学2020-2021学年高一下学期期中数学试题
名校
解题方法
4 . 已知点
是锐角
的外心,
,
,
分别为内角
,
,
的对边,
,且
,则
的值为_____ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.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/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/fc8c65bea2c80af038768b74250c694e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ca951ca55d59fa2fac36a6350b3f508.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
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解题方法
5 . 在
中,
.
(1)若
,求
的值;
(2)设向量
,
,且
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec569211c8d47b19c945e395e7395d99.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1aae237a9db73084d0c37a9324c016fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a24a8f5e8fb89381f8add6549170345.png)
(2)设向量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dd882cfac4d249d35c1863e65787925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6f3fb8582f03f22f12af648f4b6dba3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd85ca5ad669cb05fece9796a78938e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b21bdea15993d7447c9bee28f7318bc9.png)
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6 . 奔驰定理:已知
是
内的一点,
,
,
的面积分别为
,
,
,则
.“奔驰定理”是平面向量中一个非常优美的结论,因为这个定理对应的图形与“奔驰”轿车(Mercedesbenz)的logo很相似,故形象地称其为“奔驰定理”.若
、
是锐角
内的点,
、
、
是
的三个内角,且满足
,
,则( )
![](https://img.xkw.com/dksih/QBM/2021/7/10/2761151519342592/2764840447770624/STEM/087e51d1-5e63-4335-b97e-6fe598bc70e4.png?resizew=158)
![](https://img.xkw.com/dksih/QBM/2021/7/10/2761151519342592/2764840447770624/STEM/2ad46b81-7cce-42e8-a9f6-5f65b60a6e6c.png?resizew=190)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a7ffcd1925a2b1259221c6a476152f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2bbf9680f74a9ac5d934304654ce2771.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/866b81a8384cce4f24867baca2e6820c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2319b6a5373bc8eb13772b8e6d047779.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ea3c7cd2f23b4521e64a7e64844ec48.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/089e8a7f6c535fc3cd270af428d55f65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa596729b1f446947b597557f6cc32.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.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/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/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec832bb20c7265239f8736ce3fdc18d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40018175912da0930709934b329766de.png)
![](https://img.xkw.com/dksih/QBM/2021/7/10/2761151519342592/2764840447770624/STEM/087e51d1-5e63-4335-b97e-6fe598bc70e4.png?resizew=158)
![](https://img.xkw.com/dksih/QBM/2021/7/10/2761151519342592/2764840447770624/STEM/2ad46b81-7cce-42e8-a9f6-5f65b60a6e6c.png?resizew=190)
A.![]() |
B.![]() |
C.![]() |
D.![]() |
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7 . 设
的内角A、B、C满足
,则
的最小值为________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d68378acf0842d7f7d59437e0f2c1a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40dc9d5489e64013a8aa8022f5c391c.png)
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解题方法
8 . 已知
面积为12,
,则下列说法正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07160f14b3b453bebb64cb2bf96dc85a.png)
A.若![]() ![]() | B.![]() ![]() |
C.![]() ![]() | D.![]() ![]() |
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2021-07-14更新
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2755次组卷
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9卷引用:重庆市南开中学校2020-2021学年高一下学期期中数学试题
重庆市南开中学校2020-2021学年高一下学期期中数学试题(已下线)第六章 平面向量及其应用 章末测试(提升)-2021-2022学年高一数学一隅三反系列(人教A版2019必修第二册)重庆市清华中学2021-2022学年高一下学期第一次月考数学试题(已下线)高一数学下学期期中精选50题(压轴版)-2021-2022学年高一数学考试满分全攻略(人教A版2019必修第二册)(已下线)第02讲 正弦定理-【帮课堂】2021-2022学年高一数学同步精品讲义(苏教版2019必修第二册)(已下线)专题强化训练二 解三角形综合问题精选必刷题-2022-2023学年高一数学《考点·题型·技巧》精讲与精练高分突破系列(人教A版2019必修第二册)(已下线)模块二 专题2 《平面向量》单元检测篇 B提升卷 (北师大版)(已下线)模块二 《平面向量》单元检测篇 B提升卷(人教A)重庆市乌江新高考协作体2023-2024学年高一下学期第一阶段学业质量联合调研抽测(4月)数学试题
名校
解题方法
9 . 某农场有一块等腰直角三角形的空地
,其中斜边
的长度为
米,为迎接“五一”观光游,欲在边界
上选择一点
,修建观赏小径
、
,其中
、
分别在边界
、
上,小径
、
与边界
的夹角都为
,区域
和区域
内种植郁金香,区域
内种植月季花.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/14/b346e4f7-4052-4775-90c7-a90ab1f9ba9d.png?resizew=154)
(1)探究:观赏小径
与
的长度之和是否为定值?请说明理由;
(2)为深度体验观赏,准备在月季花区域内修建小径
,当
点在何处时,三条小径(
、
、
)的长度和最小?并求出最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ba602bfa3a3ffb4fb43dc0f704a7f7d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/892909e49156f7dcc0650fcd65243877.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c8ffe24cf9f327aeb241225ab15ab1a.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/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/892909e49156f7dcc0650fcd65243877.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c8ffe24cf9f327aeb241225ab15ab1a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d5bca00fa20e6e80480b9d06d2e52ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b81fb655624ff75a5eab94de9b8c8e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d62de810f5160223afa54fd882acb9b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92e6f84f2a5721303019f158d860cd5b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/14/b346e4f7-4052-4775-90c7-a90ab1f9ba9d.png?resizew=154)
(1)探究:观赏小径
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/892909e49156f7dcc0650fcd65243877.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c8ffe24cf9f327aeb241225ab15ab1a.png)
(2)为深度体验观赏,准备在月季花区域内修建小径
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/892909e49156f7dcc0650fcd65243877.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c8ffe24cf9f327aeb241225ab15ab1a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
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解题方法
10 . 已知
的内角分别为
,满足
,且![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9fc7a0c0350f0224ac784d016efa28.png)
,则以下说法中正确的有( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/825bab239d1c41bb96f3527928a61397.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ef764daec4a55cc6560b6ee46dfe5d0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9fc7a0c0350f0224ac784d016efa28.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f79b8690c922e042e422cda331fbdfc.png)
A.若![]() ![]() |
B.若![]() ![]() |
C.若![]() ![]() ![]() |
D.若![]() ![]() |
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2021-07-13更新
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1755次组卷
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6卷引用:湖北省华中师范大学第一附属中学2020-2021学年高一下学期期中数学试题
湖北省华中师范大学第一附属中学2020-2021学年高一下学期期中数学试题湖北省武汉市华中师范大学第一附属中学2021-2022学年高一下学期期中模拟检测数学试题(已下线)第六章平面向量及其应用章节验收测评卷-【精讲精练】2022-2023学年高一数学下学期同步精讲精练(人教A版2019必修第二册)重庆市第十八中学2022-2023学年高一下学期期中数学试题河南省开封市河大附中实验学校2022-2023学年高一下学期第一次月考数学试题四川省合江县马街中学校2022-2023学年高一下学期期中数学试题