名校
1 . 如图,在由三棱锥
和四棱锥
拼接成的多面体
中,
平面
,平面
平面
,且
是边长为
的正方形,
是正三角形.
(1)求证:
平面
;
(2)若多面体
的体积为16,求
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03962e215c034bbe273c45843e212fa5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e5ba482836565abad208665cf7b9972.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9165d9bfbb0f0d19eb482c2a4c1b29b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f4c3f9dd5d0343597a7f58a1989b537.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd2d28f1e7a6b17401c19c34beddcbe0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38387ba1cadfd3dfc4dea4ca9f613cea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6830ebecddbd9759be626289c408e4f3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/5/c962b9a4-e26a-424b-ae5b-4f0858d2c7c0.png?resizew=159)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31c34b18525831f3eda7bb90be0199b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a09d9d486b7f91ba933210dd013a7f2c.png)
(2)若多面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9165d9bfbb0f0d19eb482c2a4c1b29b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
您最近一年使用:0次
2023-07-04更新
|
544次组卷
|
7卷引用:江西省上高二中2021届高三年级全真模拟考试数学(理)试题
江西省上高二中2021届高三年级全真模拟考试数学(理)试题重庆市第一中学2019-2020学年高三下学期期中数学(理)试题重庆市经开礼嘉中学2020届高三下学期期中数学(理)试题(已下线)考点24 空间直线、平面的平行、垂直问题-2021年新高考数学一轮复习考点扫描第三章空间向量与立体几何 章末测评卷-2022-2023学年高二上学期数学北师大版(2019)选择性必修第一册(已下线)第一章 空间向量与立体几何 章末测试(提升)-2023-2024学年高二数学《一隅三反》系列(人教A版2019选择性必修第一册)黑龙江省饶河县高级中学2022-2023学年高二下学期期末考试数学试题
解题方法
2 . 在斜三棱柱
中,△ABC是边长为2的正三角形,侧棱
,顶点
在面ABC的射影为BC边的中点O.
![](https://img.xkw.com/dksih/QBM/2022/4/11/2955926548725760/2956560370229248/STEM/53950a70e6a04e0dbba07ab78a9b0d15.png?resizew=289)
(1)求证:面
⊥面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23d0cba2f1c74d7cdf4eefdd665d4357.png)
(2)求面ABC与面
所成锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a243eafad1f352a8b3ac805c3ec5c6e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/038a54be63c6c007b380bc862b0b14d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7c314398e26ffc7164b82946eeb4273.png)
![](https://img.xkw.com/dksih/QBM/2022/4/11/2955926548725760/2956560370229248/STEM/53950a70e6a04e0dbba07ab78a9b0d15.png?resizew=289)
(1)求证:面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/545decfe4dd2dcf6f24da7363c1bd023.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23d0cba2f1c74d7cdf4eefdd665d4357.png)
(2)求面ABC与面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3636b407d8818e15891e18db47fa0c9e.png)
您最近一年使用:0次
2022-04-12更新
|
665次组卷
|
4卷引用:江西省新余市2021届高三第二次模拟考试数学(理)试题
名校
解题方法
3 . 如图所示,底面为菱形的直四棱柱
被过三点
的平面截去一个三棱锥
(图一)得几何体
(图二),E为
的中点.
![](https://img.xkw.com/dksih/QBM/2022/1/15/2895202651045888/2924944633683968/STEM/09673f9a-6ccb-46aa-a749-bb18d347884f.png?resizew=322)
(1)点F为棱
上的动点,试问平面
与平面
是否垂直?请说明理由;
(2)设
,当点F为
中点时,求锐二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0424446817f60c18f8e4e3cc202ad99.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50007fd050316b06d42749b85d34ee94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4772621b571a6eda3ab01757a24b0c34.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9164d4bc2ff3ae9d739f7056bfe4d6df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cfbc0b5a8fbde804bd8425a4b76d207.png)
![](https://img.xkw.com/dksih/QBM/2022/1/15/2895202651045888/2924944633683968/STEM/09673f9a-6ccb-46aa-a749-bb18d347884f.png?resizew=322)
(1)点F为棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7865126ef23077f3ed6832899a600732.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a6e8736813aa28b5903358fa64c0072.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37d20ebb418c002e3bdf82ae41ede2b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e425e26fb6fc967e6e63413ccd8a9b46.png)
您最近一年使用:0次
2022-02-26更新
|
458次组卷
|
8卷引用:江西省鹰潭市2021届高三第二次模拟考理科数学试题
江西省鹰潭市2021届高三第二次模拟考理科数学试题(已下线)重难点3 空间向量与立体几何-2021年高考数学【热点·重点·难点】专练(山东专用)辽宁省抚顺市第一中学2021-2022学年高二上学期入学考试数学试题辽宁省抚顺市第一中学2021-2022学年高二上学期入学考试数学试题【全国百强校】河北衡水金卷2019届高三12月第三次联合质量测评数学(理)试题(已下线)专题20 立体几何综合——2020年高考数学母题题源解密(山东、海南专版)(已下线)专题31 空间中直线、平面垂直位置关系的证明方法-学会解题之高三数学万能解题模板【2022版】辽宁省鞍山市矿山高级中学2022-2023学年高一下学期期末数学试题
名校
解题方法
4 . 如图,在三棱柱
中,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/2021/6/1/2733809612865536/2733852613885952/STEM/a6f5a005-3c9f-4e31-a4cc-6cbebb63d32d.png)
(1)证明:平面
平面
.
(2)若
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7ad3a578f403b9e6b97fa2dc955fc11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a1be17e0a3e51cde1f50f384198e71e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f06c1cedcc4406a91783f9d37cab421e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7e3c9e7c05de9838c0c5d762720d3ef.png)
![](https://img.xkw.com/dksih/QBM/2021/6/1/2733809612865536/2733852613885952/STEM/a6f5a005-3c9f-4e31-a4cc-6cbebb63d32d.png)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3d7090639341730951c1bc3c9b6164e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31e53b212640dadf751ef7f65a78a209.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a369a75575a3656285291cc9365a8d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1c639c59d882b9d4f8c1ddbaa2b0da9.png)
您最近一年使用:0次
2021-06-01更新
|
1221次组卷
|
14卷引用:江西省2021届高三5月联考数学(理)试题
江西省2021届高三5月联考数学(理)试题河南省焦作市2021届高三考前适应性考试数学(理科)数学试题辽宁省沈阳市郊联体2021届高三四模数学试题河北省沧州市2021届高三三模数学试题河南省2021届高三高考数学(理)仿真模拟试题(二)河南省2021届高三年级仿真模拟考试(二)数学理科试题河南省2021届高三年级仿真模拟考试(二)数学文科试题宁夏吴忠市2022届高三模拟数学(理)试题2022届全国名校高考模拟冲刺卷理科数学试题(一)内蒙古赤峰二中2021-2022学年高二下学期第一次月考数学(理)试题云南省宣威市第三中学2023届高三下学期2月月考数学试题云南省通海县第一中学2023届高三上学期9月月考数学试题云南省元江哈尼族彝族傣族自治县第一中学2023届高三下学期2月月考数学试题四川省泸县第五中学2022-2023学年高二下学期3月月考理科数学试题
名校
解题方法
5 . 在四棱锥
中,底面
为直角梯形,
,
,平面
底面
,
为
的中点,
是棱
上的点,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/15/f1418db9-57f3-4269-87c1-3cc40fe6345b.png?resizew=169)
(1)求证:平面
平面
;
(2)若
,求直线
与
所成角的余弦值;
(3)若二面角
大小为
,求
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f571396be1aa4a8914a66f7d7abd6381.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90ff6d7dd48b57f03d82d2c522ee9b94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8254b52b379a420c17d38334940b073.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5729dd997ea7e8cb4cef8b7165b36e00.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18120a244d3a1f9c1688bf53eb2ad775.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/15/f1418db9-57f3-4269-87c1-3cc40fe6345b.png?resizew=169)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eefd7b101bd749d0860d3a70d13c21a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34b416412f982d9c6956b2229d6e3729.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69d2b798744645af88a4fa411344a83.png)
(3)若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a773fe6d12311dc321198697eb528ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d5bca00fa20e6e80480b9d06d2e52ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db8305c4ffbf876642440c3d28e91e9f.png)
您最近一年使用:0次
2021-05-30更新
|
718次组卷
|
3卷引用:江西师范大学附属中学2021届高三三模考试数学(理)试题
江西师范大学附属中学2021届高三三模考试数学(理)试题江西省顶级名校2021届高三下学期三模数学(理)试题(已下线)第1章 空间向量与立体几何 章末测试(提升)-2021-2022学年高二数学一隅三反系列(人教A版2019选择性必修第一册)
6 . 如图,四棱锥
中,
平面
,
,
,
,
,点
在线段
上,且
,
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/0daf84c1-2190-4ab8-8b9b-d13d1c096c8e.png?resizew=172)
(1)求证:平面
平面
;
(2)若
,求平面
和平面
所成锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34e0a957a55460c72673c0f2ee90dbb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9eee296a7d9fba487f1485c61580196f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0d5a2cd05e4476fc72271e8fdb59a9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ea236eaba1837c935c1ac157b290f70.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/30067b7b236d17af8a462f96a58d11bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb304d905125170bebfada27e7ed8960.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/0daf84c1-2190-4ab8-8b9b-d13d1c096c8e.png?resizew=172)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9332d230f25309248ff2a6161f060229.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00bab2c27eac56fffa4cd7dbe1dcdf1a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb304d905125170bebfada27e7ed8960.png)
您最近一年使用:0次
名校
7 . 已知三棱柱
中,四边形
是正方形,二面角
为直二面角,
.
![](https://img.xkw.com/dksih/QBM/2021/5/25/2728772013023232/2731982409990144/STEM/14ffd0f8-6571-4c7f-b568-09f11d22d474.png?resizew=241)
(1)求证:
;
(2)若
,
为线段
的中点,求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cea67423ce6963c0972867306169f17a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45acdbac251ca6b76a166c1242e71df9.png)
![](https://img.xkw.com/dksih/QBM/2021/5/25/2728772013023232/2731982409990144/STEM/14ffd0f8-6571-4c7f-b568-09f11d22d474.png?resizew=241)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff4fcf607b0710d12aaabd17fd053d83.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/151f7aef7d0f56e18562f5a4030cf815.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ee8456443402a25b1e25d35ff7e1c98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c4a1f5a0cdcabfcb417d26f69b337de.png)
您最近一年使用:0次
2021-05-30更新
|
624次组卷
|
2卷引用:江西省2021届高三5月适应性大练兵联考数学(理)试题
名校
8 . 如图,在空间几何体
中,平面
平面
,
平面
,
与
都是以
为底的等腰三角形,
为
的中点,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/22/5ee5cc7a-d733-428a-b93d-34c8165159ca.png?resizew=225)
(1)证明:点
在平面
内;
(2)已知
,
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9142a8490de14a87eda628ffa7e28982.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3d7090639341730951c1bc3c9b6164e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4eb7e9ad5486cf1c5e506b20c5469e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8d2d217e9bcd059908f117dfc4d4259.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4eb7e9ad5486cf1c5e506b20c5469e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7ac5396c5ea442e0364b50c1db3d2da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bb5b12692517a39c320f99a479eb055.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06201e4f55b78d8b30afb257d5a1b16b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/22/5ee5cc7a-d733-428a-b93d-34c8165159ca.png?resizew=225)
(1)证明:点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/926584088b939200d88e64318f2d4e6c.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4795ee1f96b430529934e2231b38885d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/176d2bc0a78f147873aebb260290dd15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98e384e0ffc3d599303b77ee2a12221e.png)
您最近一年使用:0次
2021-05-18更新
|
471次组卷
|
2卷引用:江西省新余市第一中学2021届高三全真模拟考试数学(理)试题
名校
9 . 如图,在四棱锥
中,
平面
,
,若
,
,
,
.
![](https://img.xkw.com/dksih/QBM/2021/5/17/2722888807063552/2723270619299840/STEM/cee8b888-3dd9-411f-bc67-1b9a89a79370.png?resizew=239)
(1)求证:
;
(2)求直线
与平面
所成的角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ffc6952e988d04f22f0fb2f7f0ab7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10df84d553a8826a7ce9bff4bf0d95b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa352e69320e35fc07f22b57b863ca5b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f144992e1cbee34868abce1e5ad38c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98823cbc09ca52df1fbcc446eba3e44f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/efc6e4b936d7a800e839a30c3839574d.png)
![](https://img.xkw.com/dksih/QBM/2021/5/17/2722888807063552/2723270619299840/STEM/cee8b888-3dd9-411f-bc67-1b9a89a79370.png?resizew=239)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d390782b8ea7016628ee68403dcbfbf3.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a4bae486bf28ab452b60a58820f3c47.png)
您最近一年使用:0次
2021-05-17更新
|
995次组卷
|
2卷引用:江西省南昌市2021届高三三模数学(理)试题
10 . 等边三角形
的边长为
,点
、
分别是边
、
上的点且
如图甲,将
沿
折起到
的位置,使四棱锥
的体积最大.连接
、
,如图乙,点
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/13/9feea4a5-a863-4c79-8308-915dec51fe9c.png?resizew=331)
(1)求证:
平面
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.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/bfb96925429b2c0a4d1a0761b4b8f5ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3aa2a83fed9bf4cb09d84a980452e346.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd5079c787292561044cc3c1437966a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ee8456443402a25b1e25d35ff7e1c98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/13/9feea4a5-a863-4c79-8308-915dec51fe9c.png?resizew=331)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b766876252d16f2e331ef2893d45cf04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9afac7c616bbb14e1ed428a3c507c7dc.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e81327fba1347334bce4c3a0ed386286.png)
您最近一年使用:0次