1 . 类比于平面三角形中的余弦定理,我们得到三维空间中的三面角余弦定理;如图1,由射线PA、PB、PC构成的三面角
,
,
,
,二面角
的大小为
,则
.
,平面
平面ABCD,
,
,求
的余弦值;
(2)当
、
时,证明以上三面角余弦定理;
(3)如图3,斜三棱柱
中侧面
,
,
的面积分别为
,
,
,各侧面所应得平面与底面所成的三个二面角分别记为
,
,
,请用文字和符号语言描述你能够得到的正弦定理在三维空间中推广的结论,并证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa26fadeee2becc192fa53d778445d52.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eac229a5e782559ffb0f271cbfc01c6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef6ab2d197160f40b72fe0abb3fe527d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a438393ddfc7da1804baf4932442bb35.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3e14113e0a7ac6b8e1faf51dbcc6dbd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0671b4776e142e17a79af5b3f0378ef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7e3c9e7c05de9838c0c5d762720d3ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f81e24376a13d648c2ed0dc73bc710e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/947c03e48c4be7485f1547817f890c53.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17cc100e36303b3566d91e4756594cf2.png)
(3)如图3,斜三棱柱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9a8181f7a7fe7f3fac872ce9534f15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e097c8d4c948de063796bd19f85b3a9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e0bd63f55069a3bc870915010b39225.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6899bf9cadae2ccdb14cbc87d4f280ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25f64fa38725c136504f723019a18dc5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e93fa313adc4ac7608ba9449fd755212.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e8d4017e1a37acb0c8e00508be472b2.png)
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2022-12-25更新
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531次组卷
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4卷引用:上海市嘉定区第一中学2022-2023学年高二上学期12月月考数学试题
上海市嘉定区第一中学2022-2023学年高二上学期12月月考数学试题广东省深圳市深圳大学附属中学、龙城高级中学第二次段考2023-2024学年高一下学期5月月考数学试题(已下线)第五篇 向量与几何 专题17 三正弦定理、三余弦定理 微点2 三正弦定理、三余弦定理综合训练(已下线)第二章 立体几何中的计算 专题一 空间角 微点13 三正弦定理与三余弦定理综合训练【培优版】
名校
2 . 已知三角形花园
,顶点
、
、
为花园的三个出入口,满足
,
,
(单位:米).
(1)求三角形花园的面积(精确到
平方米);
(2)若三角形
个内角均小于
,到三角形三个顶点距离之和最短的点
必满足
、
、
正好三等分
点所在的周角,该点所对三角形三边的张角相等,均为
.所以这个点也称为三角形的等角中心.请根据此知识求出三角形花园的最佳会合点
到三个出入口的最小距离和(满足到三个出入口的距离和最小).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.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/c5670f9370a4f8ac65a2df3a966d93ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7912f2378feefdeeed69c298a7360b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dbcae1e3ecea7312a1120e8b4c442a9.png)
(1)求三角形花园的面积(精确到
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
(2)若三角形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/231b861d6d1f1d0b9f52b041cb40eb62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b66a5b7813e902306477f91f9f4084cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e5c62f22d7afc5627fcb86599faa8e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c884b508394b3ab50734b584d9ec783c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/231b861d6d1f1d0b9f52b041cb40eb62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
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名校
3 . 如图所示,公路
一侧有一块空地
,其中
,
,
.市政府拟在中间开挖一个人工湖
,其中
都在边
上(
不与
重合,M在
之间),且
.
处,求
的长度;
(2)为节省投入资金,人工湖
的面积尽可能小,设
,试确定
的值,使
的面积最小,并求出最小面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3fe95f656b98b53f71a9d72bf0c9a4b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0ecf7d59234f76e997e02e9709f1a85.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1df54ecb4957be464432c79875c1e88d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55b9931cfb6a0ba33cb6e11e569a8cee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25dd698d57d1cf239eb8752aecaaa4f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7789a500686c7a73770404ead6af0590.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7789a500686c7a73770404ead6af0590.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/898db7807a160f0c7b17e68615699a07.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c21b46648e2a597645a3e849884d739b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2bd4f1b3a3f3e534c5c3b39266f1ac8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaf3369e0ea90e8d5cf4b6b3c45c0fd8.png)
(2)为节省投入资金,人工湖
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25dd698d57d1cf239eb8752aecaaa4f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bb4fddc8045e815ffa58cff4bed74d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25dd698d57d1cf239eb8752aecaaa4f4.png)
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2022-06-06更新
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4卷引用:上海市华东师范大学第二附属中学2023届高三上学期10月月考数学试题
(已下线)上海市华东师范大学第二附属中学2023届高三上学期10月月考数学试题江西省临川第一中学暨临川一博中学2021-2022学年高一下学期第二次月考数学试题江苏省南京市第二十七高级中学2022-2023学年高二上学期9月期初测试数学试题福建省莆田华侨中学2023-2024学年高一下学期3月月考数学试卷
名校
4 . 某水产养殖户承包一片靠岸水域.如图,
、
为直线岸线,
米,
米,
,该承包水域的水面边界是某圆的一段弧
,过弧
上一点
按线段
和
修建养殖网箱,已知
.
![](https://img.xkw.com/dksih/QBM/2021/12/21/2877362589736960/2878134138093568/STEM/5cf2c44e260345edaf70618b57930d9a.png?resizew=178)
(1)求岸线上点
与点
之间的直线距离;
(2)如果线段
上的网箱每米可获得40元的经济收益,线段
上的网箱每米可获得30元的经济收益.记
,则这两段网箱获得的经济总收益最高为多少?(精确到元)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2c3d2cba96f6f03520c0b3f6e4da03e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b90e0f35eda1a729fed485f83da5ea9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b711d09cf350b68728ace265fc88d7c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/602773cbc4969675b9e28c8fa8f77d3b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d162c29b1e484cfc87350dd68f00b85.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16d65cecaf8a3dc2953f4109c75a981e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16d65cecaf8a3dc2953f4109c75a981e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49c27ed2753bc9782bc9fa26755eb582.png)
![](https://img.xkw.com/dksih/QBM/2021/12/21/2877362589736960/2878134138093568/STEM/5cf2c44e260345edaf70618b57930d9a.png?resizew=178)
(1)求岸线上点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
(2)如果线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/513cb0e220a0fed33454151e303bcbe7.png)
您最近一年使用:0次
2021-12-22更新
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4卷引用:上海市宝山中学2022-2023学年高二上学期9月月考数学试题
上海市宝山中学2022-2023学年高二上学期9月月考数学试题上海市浦东新区2022届高三上学期一模数学试题(已下线)专题4-4 三角函数与解三角形大题归类-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)上海市复旦大学附属中学2023届高三下学期开学考试数学试题