名校
1 . 如图所示,已知多面体
中,四边形
为菱形,
为正四面体,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/2/8aed5a62-e5b8-475e-9aed-725f94c3ee4c.png?resizew=192)
(1)求证:
平面
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2fc1129846f37afdafd751627c450d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b9d54cbbf601f4583659771eb534997.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec7045cee264e93b07cdf00012bd881a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/2/8aed5a62-e5b8-475e-9aed-725f94c3ee4c.png?resizew=192)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11d27ff0b39832f094ec51e28721d739.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20af148464904e21f4374cc8fb886fba.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f22eea13efafb003e7b08a6f0bc0f2f3.png)
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2020-05-03更新
|
307次组卷
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4卷引用:河南省新乡市获嘉县第一中学2023-2024学年高二上学期第一次月考数学试题
名校
2 . 如图,在三棱台ABC﹣A1B1C1中,D,E分别是AB,AC的中点,B1E⊥平面ABC,△AB1C是等边三角形,AB=2A1B1,AC=2BC,∠ACB=90°.
![](https://img.xkw.com/dksih/QBM/2019/1/3/2110811852365824/2111689648562176/STEM/91a9089e0c8a45e083aad6aad30ce27c.png?resizew=183)
(1)证明:B1C∥平面A1DE;
(2)求二面角A﹣BB1﹣C的正弦值.
![](https://img.xkw.com/dksih/QBM/2019/1/3/2110811852365824/2111689648562176/STEM/91a9089e0c8a45e083aad6aad30ce27c.png?resizew=183)
(1)证明:B1C∥平面A1DE;
(2)求二面角A﹣BB1﹣C的正弦值.
您最近一年使用:0次
2018-12-03更新
|
1282次组卷
|
6卷引用:河南省2018届高三一轮复习诊断调研联考高三上学期联考理数试题
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解题方法
3 . 如图,已知在等腰梯形
中,
,
,
,
,
=60°,沿
,
折成三棱柱
.
![](https://img.xkw.com/dksih/QBM/2019/3/29/2171048029880320/2175300594155520/STEM/f3789eb2185b4230bebf608d40eb82c5.png?resizew=279)
(1)若
,
分别为
,
的中点,求证:
∥平面
;
(2)若
,求二面角
的余弦值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4611ceb2a28f7a7e4d24266d7f99b22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1ff7bf8ffc8a04186e3e13c1a6d5ced.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced06b71073e1bb777f326f06016ce17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09d27bd71d79cb19eb554175e4ef0867.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23dc2d2dd56fcc67698c45a6e0e48f80.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1bcc181aa254e91bfc333c966e4637d.png)
![](https://img.xkw.com/dksih/QBM/2019/3/29/2171048029880320/2175300594155520/STEM/f3789eb2185b4230bebf608d40eb82c5.png?resizew=279)
(1)若
![](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/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b32c05247f6998d7a70d31d13be4148c.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af633abfe3cb03f1836db6c570a5bcc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89c9c2c831a0552a7c934365bc49ad3f.png)
您最近一年使用:0次
2018-06-07更新
|
726次组卷
|
4卷引用:[全国市级联考】河南省洛阳市2017-2018学年高二质量检测数学(理)
名校
4 . 如图,在四棱锥
中,底面
为梯形,平面
平面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5528310855c85b21a7b627208f551b2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d52623aef17583cfb3bbbe0f84e1979c.png)
为侧棱
的中点,且
.
![](https://img.xkw.com/dksih/QBM/2018/1/18/1863277310517248/1864621339992064/STEM/879d41eecadc4db5aa97975df2fef02a.png?resizew=134)
(1)证明:
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/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5528310855c85b21a7b627208f551b2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d52623aef17583cfb3bbbe0f84e1979c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/827d63fc436eac20adaf279d57b0ea1a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/058953fc3ed0af5ddd0a44ef687f2c8d.png)
![](https://img.xkw.com/dksih/QBM/2018/1/18/1863277310517248/1864621339992064/STEM/879d41eecadc4db5aa97975df2fef02a.png?resizew=134)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/932a04304f2d4975955d4baabb2deeea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b33b7213d99a817bff19bcf740a0697c.png)
您最近一年使用:0次
2018-01-20更新
|
765次组卷
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4卷引用:河南省郑州市商丘市名师联盟 2020-2021学年高三11月质量检测巩固卷数学(理科)试题
名校
5 . 如图,四边形
和四边形
均是直角梯形,
二面角
是直二面角,
.
(1)证明:在平面
上,一定存在过点
的直线
与直线
平行;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b8e554925cc139260dd5c289805068a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ed12dbce4429a93b12a2aaad0da5520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a31a38de26ae485ae43f55feada1b226.png)
(1)证明:在平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/500df0e782bb081e608f4bc1d576afcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99d65b5127ccd01345f8bca5d8a94bc4.png)
![](https://img.xkw.com/dksih/QBM/2017/11/14/1817093975367680/1818574724825088/STEM/dd1a78c8f7c242628fdfc7bd7aa8a62c.png?resizew=136)
您最近一年使用:0次