1 . 已知直三棱柱
,
,
,
,
分别为
,
,
的中点,且![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb4bf0cd5d0f1cd6dee1eee88d34e0ad.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/19/a2389888-ef82-4d12-9a79-2114b5f1d24d.png?resizew=132)
(1)求证:
平面
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2af2626608f61a4cfbb86494bd6df0e2.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/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b470c4e195cf7a07b7a331ce4b436e03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb4bf0cd5d0f1cd6dee1eee88d34e0ad.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/19/a2389888-ef82-4d12-9a79-2114b5f1d24d.png?resizew=132)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7592c4f01c8e06c7ee90df5b9413a9f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f96c673a2381f118ea2d3efc0bca1f3.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/757ef0bdb7fbd0e05acf10023b011527.png)
您最近一年使用:0次
名校
解题方法
2 . 如图,在三棱台
中,平面
平面
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/15/83b8014c-02df-4a43-9e41-b484d60eb8b8.png?resizew=189)
(1)证明:
;
(2)求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/986ba572d8373df48c996f8c8611498c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b7d82423b6f211a7ac51a850b55e73a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f3bd47ca6cc94b6b642a57c299dcfc9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09c57d4c6ddf04ef6eaa2987378b434b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/15/83b8014c-02df-4a43-9e41-b484d60eb8b8.png?resizew=189)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b13d28cb7181257cf732af4b615fc47d.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fc6bc85b019e9d158ca1d92feed796e.png)
您最近一年使用:0次
2021-09-12更新
|
1253次组卷
|
3卷引用:广东省深圳市布吉中学2021-2022学年高二上学期期中数学试题
广东省深圳市布吉中学2021-2022学年高二上学期期中数学试题重庆市第十八中学2020-2021学年高二下学期3月月考数学试题(已下线)第34讲 利用坐标法解决立体几何的角度与距离问题-2022年新高考数学二轮专题突破精练
名校
解题方法
3 . 如图,在四棱锥P-ABCD中,
平面ABCD,
,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/2021/12/16/2873881732603904/2877184785719296/STEM/c2745f06b3344927b90306b25dafedee.png?resizew=168)
(1)证明:平面
平面PAC;
(2)求平面PCD与平面PAB夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080db3af81b29ed10144a1c2e2a4fb8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae1e04eeb4de72e5750dae77bcb6f88a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/829018a6ca0aff95d89e3f7cd943274e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09d27bd71d79cb19eb554175e4ef0867.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e713f0ba80e87438cf6273fb00cb81a7.png)
![](https://img.xkw.com/dksih/QBM/2021/12/16/2873881732603904/2877184785719296/STEM/c2745f06b3344927b90306b25dafedee.png?resizew=168)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/342d452a7b850cd3a15b23619ad39bd7.png)
(2)求平面PCD与平面PAB夹角的余弦值.
您最近一年使用:0次
2021-12-21更新
|
844次组卷
|
11卷引用:广东省茂名市2020-2021学年高二下学期期末数学试题
广东省茂名市2020-2021学年高二下学期期末数学试题广东省东莞市七校2021-2022学年高二上学期12月联考数学试题江苏省南京市中华中学2021-2022学年高三上学期期初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天津外国语大学附属滨海外国语学校2021-2022学年高二上学期10月月考数学试题安徽省安庆市第二中学2021-2022学年高二上学期12月第二次段考数学试题广东省潮州市2021-2022学年高二上学期期末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黑龙江省齐齐哈尔市恒昌中学校2022-2023学年高三上学期开学考试数学试题重庆市荣昌永荣中学校2021-2022学年高二上学期期末数学试题河南省洛阳市洛宁县第一高级中学2022-2023学年高二下学期2月月考数学文科试题
2013·山东临沂·一模
名校
解题方法
4 . 如图所示,在矩形
中,
,点
为
的中点,沿
将
折起,
.
![](https://img.xkw.com/dksih/QBM/2021/12/17/2874442176348160/2880371580542976/STEM/ab23f097-daac-4ddc-97b9-3af49faa25f1.png?resizew=192)
(1)求证:平面
平面
;
(2)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f80f51c31583fea58fde645474d60b8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2c3d2cba96f6f03520c0b3f6e4da03e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/372629a8666de1e9bac3e7daadcac7b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5595129319f9f5f069297ddb1455f97a.png)
![](https://img.xkw.com/dksih/QBM/2021/12/17/2874442176348160/2880371580542976/STEM/ab23f097-daac-4ddc-97b9-3af49faa25f1.png?resizew=192)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e604d7d83d9b6cfcdd566774f58c890b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/607543bb9f55b8a141ed2d6cf0e1a20b.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7abd284f76d9f5769bc189508ce2572b.png)
您最近一年使用:0次
2021-12-25更新
|
392次组卷
|
10卷引用:广东省广州市第八十九中学2021-2022学年高二上学期第一次月考数学试题
广东省广州市第八十九中学2021-2022学年高二上学期第一次月考数学试题福建省泉州科技中学2021-2022学年高二上学期期中考试数学试题山东省烟台市莱州市第一中学2021-2022学年高三上学期12月月考数学试题(已下线)2013届山东临沂高三5月高考模拟理科数学试卷(已下线)2014年高考数学(理)二轮复习体系通关训练3-d3练习卷四川省武胜烈面中学校2019-2020学年高二下学期开学考试数学(理)试题(已下线)专题02+空间向量与立体几何大题专项练习-2020-2021学年【补习教材·寒假作业】高二数学(人教A版2019)(已下线)专题17+空间向量与立体几何大题专项练习-2020-2021学年【补习教材·寒假作业】高二数学(理)(人教A版)(已下线)专题17 空间向量与立体几何大题专项练习河南省郑州市第一〇二高级中学2023-2024学年高二上学期10月月考数学试题
名校
5 . 如图,在四棱锥
中,底面
是平行四边形,
,
,
,
,
,
分别为
,
的中点,
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b0849016506bbcf052981f9cf25ab06.png)
![](https://img.xkw.com/dksih/QBM/2021/8/31/2797809120796672/2798733108690944/STEM/eef71ae0-718a-41db-9570-bf13e74cb0d3.png?resizew=268)
(1)证明:
;
(2)求直线
与平面
所成角的正弦值.
![](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/0aedf65d7d930fdb972d4802c0dea8b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced06b71073e1bb777f326f06016ce17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e65a3e478bb87d094e3a0af30dd10ae8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bb28f1ebbdcd6c304d8a8d0ea28aae0.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/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f9425630dcfe5a824c44904d4f71e13.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b0849016506bbcf052981f9cf25ab06.png)
![](https://img.xkw.com/dksih/QBM/2021/8/31/2797809120796672/2798733108690944/STEM/eef71ae0-718a-41db-9570-bf13e74cb0d3.png?resizew=268)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98f1c54b7a2afc6bcab38ddd209f60d5.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f50b3ae183997b707d16eb4e7f6712fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c52b9478a450d15ff31eb1212a39ee6.png)
您最近一年使用:0次
2021-09-01更新
|
431次组卷
|
4卷引用:广东省深圳市龙岗区平冈中学2021-2022学年高二上学期9月第一次月考数学试题
6 . 如图,四边形
和
都是正方形,且平面
平面
,
、
分别是
、
的中点,点
在线段
上.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/12/2c2aad04-f76b-4ada-a208-3f9d0c5aa16a.png?resizew=164)
(1)求证:
;
(2)若二面角
的大小为45°,求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b32c05247f6998d7a70d31d13be4148c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cf9a6db3571fa57bfa2d5e4d44c51b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b32c05247f6998d7a70d31d13be4148c.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/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/12/2c2aad04-f76b-4ada-a208-3f9d0c5aa16a.png?resizew=164)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da78c917ab3631b4a5ba70ef76eb4219.png)
(2)若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e62555c64bf39344c114f8e08bca6ae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f50b3ae183997b707d16eb4e7f6712fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22ce50ba5e349425274f05d46d120a74.png)
您最近一年使用:0次
名校
7 . 如图所示,在四棱锥
中,底面
为直角梯形,
,
,平面
底面
,
为
的中点,
为
的中点,
,
,
.
;
(2)求二面角
的余弦值.
![](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/4a0e5697eca3f5205cb7b343648240bf.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/b099921916da2b2e4a63f273b90be16e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5729dd997ea7e8cb4cef8b7165b36e00.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18120a244d3a1f9c1688bf53eb2ad775.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d84733f9dc908ceb11459cc2aed580ab.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37d02d4063639138f0cf61426fac69f8.png)
您最近一年使用:0次
2021-12-22更新
|
361次组卷
|
5卷引用:广东省广州市增城区增城中学2021-2022学年高二上学期第二阶段测试数学试题
广东省广州市增城区增城中学2021-2022学年高二上学期第二阶段测试数学试题广东省揭阳市揭东区第三中学2022-2023学年高二上学期第一次质量检测数学试题河南省濮阳市2018届高三第二次模拟考试数学(理)试题(已下线)人教B版2019选择性必修第一册综合测试(能力提升)-2020-2021学年高二数学单元测试定心卷(人教B版2019选择性必修第一册)甘肃省天水市第一中学2023-2024学年高一下学期第二次段中检测(6月)数学试题
名校
8 . 如图,在三棱柱
中,
平面
,
,
,
是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/9/3c626734-d57a-49a0-9f29-71b492988d52.png?resizew=151)
(1)求证:
平面
;
(2)求平面
与平面
夹角的余弦值;
(3)在线段
上是否存在一点
,使得
与平面
所成角的正弦值为
,若存在,求出
的长;若不存在请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a8bfe2553e852df73185d017c0a62fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29ba708880f5eb782acbf2c961c2494c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/9/3c626734-d57a-49a0-9f29-71b492988d52.png?resizew=151)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/307807ee10071bafbe922eb18d2517d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99b16cff607cdc2d69afc70dc778acbb.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7935fe3125f247b7bea4f065ce9ad985.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(3)在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdba1337ec85fa9722cb4b320a82ae6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7935fe3125f247b7bea4f065ce9ad985.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69a8b76e36783a69d14ec54af82c7df0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63a253c7fdf589ee3dece13d5b5b5732.png)
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2021-10-01更新
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3卷引用:广东省深圳市北京师范大学南山附属学校2021-2022学年高二上学期期中数学试题
解题方法
9 . 已知双曲线
的右焦点为
,一条渐近线方程为
.
(1)求双曲线
的方程;
(2)记
的左、右顶点分别为
,过
的直线
交
的右支于
两点,连结
交直线
于点
,求证:
三点共线.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83bf4fd84818abac17a9d21237ac5ce5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63309dbc3612815f6dbdee23d9a10adc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b386e2c5d9ad7cec404ce5c40dbebe42.png)
(1)求双曲线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
(2)记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e52586ca2a3b783bc8092415e2d4bf6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7789a500686c7a73770404ead6af0590.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e5c62f22d7afc5627fcb86599faa8e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d599059e6b2c918ab15ee22611b6962.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6af3a2aaf87857cd944ae8a39b469da4.png)
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7卷引用:广东省2022届高三上学期综合能力测试(一)数学试题
广东省2022届高三上学期综合能力测试(一)数学试题(已下线)第04讲 双曲线的简单几何性质-【帮课堂】(已下线)3.2.2双曲线的简单几何性质(备作业)-【上好课】2021-2022学年高二数学同步备课系列(人教A版2019选择性必修第一册)(已下线)专题6.2 期中押题检测卷(考试范围:第1-3章)2(中)-【满分计划】2021-2022学年高二数学阶段性复习测试卷(苏教版2019选择性必修第一册) (已下线)专题41 盘点圆锥曲线中的中点弦及焦点弦问题——备战2022年高考数学二轮复习常考点专题突破(已下线)专题47 盘点圆锥曲线中的几何证明问题——备战2022年高考数学二轮复习常考点专题突破(已下线)重难点突破10 圆锥曲线中的向量问题(五大题型)
名校
解题方法
10 . 如图,在四棱锥
中,平面
平面
,
为等边三角形,四边形
为矩形,
为
的中点.
![](https://img.xkw.com/dksih/QBM/2022/1/15/2895071987507200/2896682430193664/STEM/935bf137-d54b-4a81-9344-ebc7d729d024.png?resizew=163)
(1)证明:平面
平面
;
(2)若
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cf9a6db3571fa57bfa2d5e4d44c51b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2205cffebf8c4d5f81d15ed7b85c8936.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://img.xkw.com/dksih/QBM/2022/1/15/2895071987507200/2896682430193664/STEM/935bf137-d54b-4a81-9344-ebc7d729d024.png?resizew=163)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d28c625d7ac6878957facc8274d459c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c4e4a162f12d12a082b8d8fdd1aeab9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c76abad7103e74e5613a802475f1c0f9.png)
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