如图,菱形
的边长为4,
,矩形
的面积为
,且平面
平面
.
![](https://img.xkw.com/dksih/QBM/2018/11/12/2073963084849152/2074098955001856/STEM/f433a2d2364744e080c3674e35efb657.png?resizew=152)
(1)证明:
;
(2)求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea4f5eec0addba78f2e0cdfb7ecc59a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ac66de8543430fd51e7c18042e626dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd3304e23f3b0f9569c4140ca89b6498.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed9c7b69462dc9226e35ddac8f179cf0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/2018/11/12/2073963084849152/2074098955001856/STEM/f433a2d2364744e080c3674e35efb657.png?resizew=152)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/589ddae20626f9aaac616d2a3b5d95bd.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe3393896bc6a5b36e61d4fb3d668a3a.png)
更新时间:2018-11-12 19:08:02
|
【知识点】 面面角的向量求法
相似题推荐
解答题-问答题
|
适中
(0.65)
名校
解题方法
【推荐1】如图,在四面体
中,
,
分别是线段
,
的中点,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/27/9c4dbc1a-e54f-4e2f-9dab-e12948a11cb2.png?resizew=147)
(1)证明:平面
平面
;
(2)若二面角
为
,求二面角
的余弦值.
![](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/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b19bfed56d8c7bd9067ee4d23dae0dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbb6e4368e1158045340ea765cc318b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a05e0ab55e325fb3b85fc8ca9c27c76.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/27/9c4dbc1a-e54f-4e2f-9dab-e12948a11cb2.png?resizew=147)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/557e120c066e17ba3eee00410cbed573.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
(2)若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35c079889aea502b5783046f78728eb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79a97bb4dcfab4ec7539bc783d563c49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da0f73cf7ab0c2a8a0099cb2873c81f4.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐2】如图,四棱锥
中,PD⊥平面ABCD,底面ABCD是正方形,
,E为PC中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/13/a47500fa-3ec7-43b1-96cc-d2ca5013de7b.png?resizew=193)
(1)求证:DE⊥平面PCB;
(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/99926bf272cd757f0985c69b390ebcce.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/13/a47500fa-3ec7-43b1-96cc-d2ca5013de7b.png?resizew=193)
(1)求证:DE⊥平面PCB;
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9eaa13915786802de6a540d56dec821b.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐3】在如图所示的几何体中,四边
是矩形,
,四边形
等腰梯形,
,
,且平面
平面
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/14/c30152ee-94a1-454a-8d1e-382590d1f4a7.png?resizew=185)
(1)过
与
平行的平面与
交于点G.求证:G为
的中点;
(2)求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0041488020a3e19377b18a70fbf82e7c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b32c05247f6998d7a70d31d13be4148c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06772d7ccc921f77319c503c23326be2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aeedb5f361a1baff6338436fff6c471d.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/b3b2e39685f8fcf4ce519cf5233a4d58.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/14/c30152ee-94a1-454a-8d1e-382590d1f4a7.png?resizew=185)
(1)过
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c6eef5161fff77cef69133326c1739d.png)
您最近一年使用:0次