将
沿它的中位线
折起,使顶点
到达点
的位置,且
,得到如图所示的四棱锥
,若
,
,
为
的中点.
平面
;
(2)求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef227e3c17e425d6809b50489f83f50b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1fd0b59a8d94c6e0b7a89c43f048247.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7277341c0e7f681a37d41c9df4bf7153.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/822ba132ca9dd0d4a050659aef3c9b26.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8d2d217e9bcd059908f117dfc4d4259.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e6c2dad46a9052a4185a4f7b4ae8a2e.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/beb4c17acd5f41213dfea07dd2e5a95c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f571a1aac46c6d0cf440c0ec2846bf9.png)
更新时间:2024-02-03 09:01:29
|
相似题推荐
解答题-证明题
|
适中
(0.65)
【推荐1】如图,在四棱锥Р一ABCD中,底而ABCD为菱形且
,O为AD中点,
,
.
![](https://img.xkw.com/dksih/QBM/2021/1/5/2629726432952320/2636072511135744/STEM/52270f9036a44878b1bbb94f93fd3b8b.png?resizew=232)
(1)求证:直线
平面POB;
(2)点M在线段PC上,且二面角
的大小为
,求直线MB与平面PBD所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae139b51956b9281d73d9ba82b875e46.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a828afde82bd1784ae9b8f96a599c0cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e99998f33ad6edab18180627d4903dcc.png)
![](https://img.xkw.com/dksih/QBM/2021/1/5/2629726432952320/2636072511135744/STEM/52270f9036a44878b1bbb94f93fd3b8b.png?resizew=232)
(1)求证:直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca5dd496ee0c1170ef6dcc48266ee444.png)
(2)点M在线段PC上,且二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0363b5557dad15f10d5c8ae474bc4368.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d5bca00fa20e6e80480b9d06d2e52ee.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐2】如图1,四边形
是边长为2的正方形,四边形
是等腰梯形,
,现将正方形
沿
翻折,使
与
重合,得到如图2所示的几何体,其中
.
![](https://img.xkw.com/dksih/QBM/2022/5/17/2981296698974208/2981510505218048/STEM/bcf1d9d5f452484ca5ca719a5c8ed073.png?resizew=348)
(1)证明:
平面
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85ea9840063279d79026d75027799b44.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38d42170c7d4249f6b390823606c18c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0740b166921dcaacf9a3e4a2515e3625.png)
![](https://img.xkw.com/dksih/QBM/2022/5/17/2981296698974208/2981510505218048/STEM/bcf1d9d5f452484ca5ca719a5c8ed073.png?resizew=348)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a22d6b860f06fe23618b0d3de6768fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3cb3ccef834032b6e09cdb50103c3e75.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c5257cdb42c9f955cee8d4e428ce5ed.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐1】如图,
为圆
的直径,点
为圆
上的一点,且
,点
为线段
上一点,且
,
垂直于圆
所在的平面.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/a5bb5faa-bd18-41da-a1d5-278192febd4a.png?resizew=162)
(1)求证:
平面
;
(2)若
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e20c1b7f55cd8e68a7c3aa58bc944c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b544ef48ca69eaeabcdbca45249881fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/a5bb5faa-bd18-41da-a1d5-278192febd4a.png?resizew=162)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97f30533da2e1d2a958dc906c37eba9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/300ee27f04188cb8ee5e20394c8f50fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/850319b7098a23b859791d7da3e63e74.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】如图,在四棱锥
中,
平面
,
,
,
是等边三角形,
为
的中点.![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
平面
;
(2)若
,求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97f30533da2e1d2a958dc906c37eba9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e106f4233be16e98f2c1bf9f1635622.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a11029ca6b4b9e7f777af0280cf163c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a301baf6cc0628366e6661a87a2d93ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3da7bcea5a45eeae211f5851f12a7517.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fd17a66a2af938c89e46f22e4d893b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1633988fd62a652de726ee92a917b52d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/218054144a13435580cd132b9459546c.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c19f0fcacac715a1200770516d1e4a67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c09afc70f448545336304333d5b5658b.png)
您最近一年使用:0次