如图长方体
中,
,
,过点
的平面
与此长方体的面相交,交线围成一个边长为5的菱形.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/2/9faeedd4-0f73-4dce-b40a-a65ae76fd492.png?resizew=108)
(1)在图中画出这个菱形(说明画法,但不必证明);
(2)若平面
与
的交点为F,求直线CF与平面
所成的角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b37750daa8ba3b3fe3e9e2092f81c848.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac5e1093a147c521c5e8d0d5e266db54.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1241216f3c1cb5e73043dd1037f556d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/2/9faeedd4-0f73-4dce-b40a-a65ae76fd492.png?resizew=108)
(1)在图中画出这个菱形(说明画法,但不必证明);
(2)若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
更新时间:2021-01-03 19:43:22
|
【知识点】 线面角的向量求法
相似题推荐
解答题-问答题
|
较易
(0.85)
解题方法
【推荐1】如图,已知三棱锥O﹣ABC的侧棱OA,OB,OC两两垂直,且OA=1,OB=OC=2,E是OC的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/29/e5c24a64-748e-4eba-bf2a-dbee4c2c3011.png?resizew=179)
(1)求异面直线BE与AC所成角的余弦值;
(2)求直线BE和平面ABC的所成角的正弦值.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/29/e5c24a64-748e-4eba-bf2a-dbee4c2c3011.png?resizew=179)
(1)求异面直线BE与AC所成角的余弦值;
(2)求直线BE和平面ABC的所成角的正弦值.
您最近一年使用:0次
解答题-证明题
|
较易
(0.85)
【推荐2】如图,在四棱锥
中,平面
底面
,
,点
为棱
的中点.
(1)证明:
;
(2)求直线
与平面
所成角的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b60a5d57f5301de2f3b3b1a5a5853f2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8ea26e11d345ec32d0a42587fe0176d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/13/78ee3c7d-5873-42ba-88e6-84b39b3dbbb6.png?resizew=171)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c38bbe49284a2ceab26001ced8cfd56.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
您最近一年使用:0次