如图,在四棱锥
中,底面ABCD是矩形,侧棱
底面ABCD,点E是PD的中点,
,
.求平面EAC与平面PAB夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced06b71073e1bb777f326f06016ce17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9bd628837add19267c186fbff246076.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/30/e5aa7761-c722-4d4d-9a20-a9018229becb.png?resizew=145)
更新时间:2023-11-29 11:01:50
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【知识点】 面面角的向量求法
相似题推荐
解答题-问答题
|
较易
(0.85)
解题方法
【推荐1】如图,在四棱台
中,底面
是菱形,
,
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/16/49b2e079-2571-4fa3-88b5-eb6c650030ee.png?resizew=164)
(1)求三棱锥
的体积;
(2)求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8115c7ad0f0fda71c1b986ebc677bb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85d7e19a17928e09a22b79e84f5f14de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/16/49b2e079-2571-4fa3-88b5-eb6c650030ee.png?resizew=164)
(1)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07cfcd1c81b27ad23408261c64528c80.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da7977ab975efa6411cc17de39be70d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c52091eb745de866044477641a7c55f.png)
您最近一年使用:0次
解答题-问答题
|
较易
(0.85)
解题方法
【推荐2】在棱长为
的正方体
中,
为正方形
的中心.
![](https://img.xkw.com/dksih/QBM/2021/3/18/2680408089903104/2684978454888448/STEM/8a1ba6d009bb4413bc7ac96a532846a3.png?resizew=191)
(1)求
与平面
所成角的大小;
(2)求二面角
的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ebb05874eb3353d754af24c9974273e.png)
![](https://img.xkw.com/dksih/QBM/2021/3/18/2680408089903104/2684978454888448/STEM/8a1ba6d009bb4413bc7ac96a532846a3.png?resizew=191)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaf1438142deeac876fc7dc50552e552.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e58fd1382be598f595fca9a351cb764d.png)
您最近一年使用:0次