名校
解题方法
1 . 在四棱锥
中,底面
是正方形,
为棱
的中点,
,
,再从下列两个条件中任选一个作为已知,求解下列问题.条件①:平面
平面
;条件②:
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/8/a7638541-d452-4139-afd1-ce0d1020b4ea.png?resizew=160)
(1)求证:
平面
;
(2)求平面
与平面
夹角的余弦值;
(3)求点
到平面
的距离.
注:如果选择条件①和条件②分别解答,按第一个解答计分.
![](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/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db27b7f29d7d01b2692f217bc3079fc4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f83a04565a8ebaa111894b724b0ba266.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/4cbb05b8b630052ff544249ebd72d95d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/8/a7638541-d452-4139-afd1-ce0d1020b4ea.png?resizew=160)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7aebaf06bb1c96aecf49603c6a6bfcea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(3)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7aebaf06bb1c96aecf49603c6a6bfcea.png)
注:如果选择条件①和条件②分别解答,按第一个解答计分.
您最近一年使用:0次
2023-01-06更新
|
806次组卷
|
4卷引用:北京一零一中学2023届高三下学期开学考数学试题
2 . 如图,正方形
和正方形
所在的平面互相垂直.
是正方形
及其内部的点构成的集合,
是正方形
及其内部的点构成的集合.设
,给出下列三个结论:
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/28/d35f0385-5285-4413-83f0-df82f7542b8a.png?resizew=149)
①
,使
;
②
,使
;
③
,使
与
所成的角为
.
其中所有正确结论的个数是( )
![](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/739684866f4fd7603a0cd322855437db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9114ab74cce6ba370d26f7a2a5ea135.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b32c05247f6998d7a70d31d13be4148c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced06b71073e1bb777f326f06016ce17.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/28/d35f0385-5285-4413-83f0-df82f7542b8a.png?resizew=149)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/621364e23bd8e4ab2d4953cd9074deaa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46e5c289b8aabdbfba95c7fd1e1842f4.png)
②
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/621364e23bd8e4ab2d4953cd9074deaa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4763b3c7fe0db6e03a3c25853d3f7f12.png)
③
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/621364e23bd8e4ab2d4953cd9074deaa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b46c607b3deac746c0ef3389ad8f65c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7785afeeaf274892253d04b4f693b367.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be6a6301878fed2a01413020b27310a5.png)
其中所有正确结论的个数是( )
A.0 | B.1 | C.2 | D.3 |
您最近一年使用:0次
解题方法
3 . 如图所示为圆锥
,已知其侧面的展开图是圆心角为
,面积为
的扇形.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/4/8d5b44ac-fca1-489a-a4eb-13802eb41de6.png?resizew=156)
(1)求圆锥
的体积;
(2)设
和
是底面圆周上两点,且平面
平面
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18e5ef91fb27dd684a27ae7f1993cfba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d49f8a63ddbca52039fa9ab44cda6b29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20b3a91ccf6028608cd03df7072f6536.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/4/8d5b44ac-fca1-489a-a4eb-13802eb41de6.png?resizew=156)
(1)求圆锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18e5ef91fb27dd684a27ae7f1993cfba.png)
(2)设
![](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/66aa4fc8af46e05cb31701f7cffabd20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b31d6fd94ea20abb4d95c2ff3231cb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a3965b2537b3aa3379be73e275be5db.png)
您最近一年使用:0次
名校
4 . 如图,在四棱锥
中,底面
为直角梯形,
//
,
,
,平面
平面
,
,
.
;
(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/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce4ab7e657f01bdfa235f8c4d6681d13.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7df3cbb0e21389791a038f7a9ce6a327.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/d0453cfd7e92bf7746a88280b9e7b580.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62974d34de3a12418d6b700420afd1b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0530f462e5ec1e58c46e1f7644d0cc21.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02535e1a690ca111ca7a395a1bf48080.png)
您最近一年使用:0次
2024-03-06更新
|
1216次组卷
|
7卷引用:专题03 少丢分题目强化卷(第二篇)-备战2021年新高考数学分层强化训练(北京专版)
(已下线)专题03 少丢分题目强化卷(第二篇)-备战2021年新高考数学分层强化训练(北京专版)2020届山东省济宁市嘉祥一中高三第四次质量检测数学试题甘肃省平凉市庄浪县紫荆中学2024届高三上学期第一次模拟考试数学试题(已下线)重难点12 立体几何必考经典解答题全归类【九大题型】广东省广州市四中2023-2024学年高二下学期3月月考数学试题内蒙古自治区呼和浩特市剑桥中学2023-2024学年高二下学期第一次(3月)月考数学试题(已下线)专题06 空间直线﹑平面的垂直(一-《知识解读·题型专练》(人教A版2019必修第二册)
名校
5 . 在四棱锥
中,侧面
底面
,
,
为
中点,底面
是直角梯形,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/28/a3e4129d-dc8f-414f-b098-0df3838bbdcf.png?resizew=206)
(1)求证:
平面
;
(2)求三棱锥
的体积;
(3)点Q在线段PC上,平面BDQ和平面PBD的夹角为
,求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/342d452a7b850cd3a15b23619ad39bd7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37002ada5d194d4d062fa3285d7d9824.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](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/4795ee1f96b430529934e2231b38885d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16114c73382b18f060150f2ab1f1484d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/833cfda415649b832cc136caed392753.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/28/a3e4129d-dc8f-414f-b098-0df3838bbdcf.png?resizew=206)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7175df06e33cad4e6bbc3f2f6b0a2986.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1112ffa328ed486ffc5e4a605eb510e.png)
(3)点Q在线段PC上,平面BDQ和平面PBD的夹角为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79a97bb4dcfab4ec7539bc783d563c49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f35bc79c32da72e17e239129bb42469a.png)
您最近一年使用:0次
2023-08-27更新
|
943次组卷
|
2卷引用:北京市景山学校2022届高三上学期期中考试数学试题
名校
6 . 如图1,在平面四边形
中,
∥
,
,将
沿
翻折到
的位置,使得平面
⊥平面
,如图2所示.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/12/79c91260-0750-4710-adea-510cf7121b90.png?resizew=324)
(1)设平面
与平面
的交线为
,求证:
;
(2)在线段
上是否存在一点
(点
不与端点重合),使得二面角
的余弦值为
,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d96e070966ddc1d779fcfae475715936.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd8bf6b4c15f19b78f979716b3d4f0f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2205cffebf8c4d5f81d15ed7b85c8936.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dea2ae9d515f9ab351ad72306b776ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72e49817548cb45b3d1e58570644c6fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc9c9cfa597b444b5c9dbae7a825a695.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/12/79c91260-0750-4710-adea-510cf7121b90.png?resizew=324)
(1)设平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5da631296d53a08d56fb5f9bec2376c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc9c9cfa597b444b5c9dbae7a825a695.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa145a3e4f18f784ddf4869e0bf904c5.png)
(2)在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c2bc5e50b8dfa02601c70822252854a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a4b4e098c6194f55462b24f552f5967.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64f1145c162038df3c7184d9201c628e.png)
您最近一年使用:0次
2023-02-11更新
|
1114次组卷
|
7卷引用:北京市石景山区2022届高三一模数学试题
北京市石景山区2022届高三一模数学试题北京卷专题20空间向量与立体几何(解答题)(已下线)必刷卷02-2022年高考数学考前信息必刷卷(新高考地区专用)北京市昌平区第二中学2022-2023学年高二上学期10月月考数学试题重庆市2023届高三下学期开学摸底数学试题云南省昆明市第一中学2022-2023学年高二下学期期中考试数学试题(已下线)第09讲 拓展三:二面角的传统法与向量法(含探索性问题,7类热点题型讲练)-【帮课堂】2023-2024学年高二数学同步学与练(人教A版2019选择性必修第一册)
7 . 如图,在几何体
中,底面四边形
是正方形,平面
和平面
交于
.
(1)求证:
;
(2)若
,
,
,
,再从条件①,条件②,条件③中选择一个作为已知,使得几何体
存在,并求二面角
的余弦值.
条件①:平面
平面
;
条件②:平面
平面
.
条件③:
,
;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9165d9bfbb0f0d19eb482c2a4c1b29b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23ba3f676fda6a2aaaa55c9f32874a51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10fc7991ea17d54ff5f4445ac5699463.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/666734423f1818d76a74f171b7420b68.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aeedb5f361a1baff6338436fff6c471d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/869dbfaf24d441c4ce3a2b8db86cd2e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/678988261e6fd7c4f1199c0204a8045d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9165d9bfbb0f0d19eb482c2a4c1b29b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98e384e0ffc3d599303b77ee2a12221e.png)
条件①:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79c1acdd27cebb11e0266464b03b3afb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
条件②:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec2af539ca4fdc2fa94d4986537b6598.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
条件③:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8baaea02eaa7e473fb2a8f84ba575c25.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd40e867f1d3377cf4fb9ae730d04cf7.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/9/39c57e43-3369-43b9-bfb8-3cfd532e567a.png?resizew=167)
您最近一年使用:0次
2023-02-01更新
|
389次组卷
|
2卷引用:北京市第十三中学2023届高三上学期12月月考测试数学试题
8 . 如图,在五面体
中,四边形
是边长为2的正方形,平面
平面
,
.
平面
;
(2)求证:平面
⊥平面
;
(3)在线段
上是否存在点
,使得
平面
?说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9165d9bfbb0f0d19eb482c2a4c1b29b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d28c625d7ac6878957facc8274d459c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43fc9469774a19627b3412d1e8588702.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6785c7c85a503531649f9c9b4cbfcf04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/369eb8ad56da7dc1cdb7c43762be4bee.png)
(2)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/369eb8ad56da7dc1cdb7c43762be4bee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b32c05247f6998d7a70d31d13be4148c.png)
(3)在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e713c9d539ed8c896a77b9433748bea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/369eb8ad56da7dc1cdb7c43762be4bee.png)
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2024-03-29更新
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1888次组卷
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8卷引用:【区级联考】北京市昌平区2019届高三第一学期期末数学(文)试题
【区级联考】北京市昌平区2019届高三第一学期期末数学(文)试题北京市通州区2019-2020学年高一(下)期末数学试题(已下线)2.3.4 平面与平面垂直的性质-2020-2021学年高一数学课时同步练(人教A版必修2)(已下线)第十三章 立体几何初步(单元重点综合测试)-单元速记·巧练(苏教版2019必修第二册)(已下线)专题20 空间直线、平面的垂直-《重难点题型·高分突破》(人教A版2019必修第二册)(已下线)11.4.2平面与平面垂直-同步精品课堂(人教B版2019必修第四册)(已下线)专题05 立体几何初步(2)-期末考点大串讲(苏教版(2019))(已下线)专题08 期末必刷解答题专题训练的7种常考题型归类-期末真题分类汇编(北师大版2019必修第二册)
9 . 如图,在四棱锥
中,底面
是直角梯形,
,
,
为等边三角形,且平面
底面
,
,
,
,
分别为
,
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/30/18ce9b9a-e118-42a6-a225-94d3af90631a.png?resizew=186)
(1)求证:
平面
;
(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/ee8ef58be8708144272538ee427fb92c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce0d7095ddd69d6ceaf1065b1bc2c79d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2205cffebf8c4d5f81d15ed7b85c8936.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6045266f6db39e41b7abde762d9e9a57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d783fe7f3ce673d5d21281174e7a7968.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/30/18ce9b9a-e118-42a6-a225-94d3af90631a.png?resizew=186)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acf2bc3dd1f1ae5d5e28b0366f454ec1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6c020d9691ea4150813a7dcf9f87fc0.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6c020d9691ea4150813a7dcf9f87fc0.png)
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10 . 如图,在三棱锥
中,平面
平面
,
,O为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/f286d8c8-7f2c-43ea-bcd3-2a27f3b22270.jpg?resizew=209)
(1)证明:
;
(2)若
是边长为1的等边三角形,点E在棱
上,
,且三棱锥
的体积为
,求二面角
的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcf6dc837ae85207789b94d109c5c2eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e735a28578ba191da6d4f3b0f8e8729.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/f286d8c8-7f2c-43ea-bcd3-2a27f3b22270.jpg?resizew=209)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b01898d4ad9757e07bddd6c26e59d1f9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4807ca16360c0cca436e59d4be98f626.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46d76c5ac5c9f0a2ec064487c02c476e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69a8b76e36783a69d14ec54af82c7df0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/324d453870b345da0c41977290192f94.png)
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