如图,在三棱锥
中,已知
平面ABC,
,
,
,求二面角
的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/615fc8790237a1b09af51d6bcad6b595.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9332278351ab92e03e984e9279dd06a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/967f74b8993c61634ceed95edca05ffd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5a2fd95dfda3f70bc2d9fcd8380bf99.png)
![](https://img.xkw.com/dksih/QBM/2022/2/11/2914360306114560/2931950995652608/STEM/bc42d86e-44e7-43f3-be32-a874ce2430d7.png?resizew=140)
21-22高二·全国·课后作业 查看更多[2]
更新时间:2022-03-08 19:32:28
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【知识点】 面面角的向量求法
相似题推荐
解答题-证明题
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【推荐1】如图,在四棱锥
中,平面
平面ABCD,E为AD的中点,
,
,
,
,
.
(1)求证:平面
平面PCD;
(2)求二面角
的余弦值;
(3)在线段PE上是否存在点M,使得
平面PBC?若存在,求出点M的位置:若不存在,说明理由.
![](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/db27b7f29d7d01b2692f217bc3079fc4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9e22143a3f0cb2de51f382836cc274e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c897a54f2e36bc4b52fba74b41c89d2d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2667ef2f661c8e3b0ef2c3e96892495f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/037b342a682cbd4241855a243da3c016.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/25/ea881b6d-f39a-4e82-ba86-3df93141be18.png?resizew=169)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e18a224786bea8ad04fe497466d7d4a.png)
(3)在线段PE上是否存在点M,使得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0457394ce4f2dc8d940c565c94dcf557.png)
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解答题-问答题
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【推荐2】已知四棱锥
的底面为直角梯形,
,
,
底面
,且
,
是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/12/041e0fb6-3652-42ac-9a4c-2006dc77bb3f.png?resizew=148)
(1)证明:平面
平面
;
(2)求平面
与平面
所成锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10df84d553a8826a7ce9bff4bf0d95b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2b377f22aafd3742ad860f77abaacef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b879e4b8a2e0dc40fdd94932ea8e9bb6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/12/041e0fb6-3652-42ac-9a4c-2006dc77bb3f.png?resizew=148)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53bdef2e7a7929ad6190302ab44c46c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17c5ef850e256c98ca4f033999e61311.png)
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【推荐3】如图,已知四边形
和
都是菱形,平面
平面
,且
,.
(Ⅰ)求证:
;
(Ⅱ)求二面角
的余弦值.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/1/2da1eb90-4838-4322-af2d-ea4584da1f9d.png?resizew=170)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ac61c24f99a4e466f1e2ea011893866.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9edc50f7febbc2d5d8dcdc23a3630a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0671b4776e142e17a79af5b3f0378ef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9edc50f7febbc2d5d8dcdc23a3630a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8602399210ddeddbd36323e01f1e4171.png)
(Ⅰ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d882575eacaf1c01c7054214a3dd9f7.png)
(Ⅱ)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0715b04d494f97e6efe2ff694388c73.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/1/2da1eb90-4838-4322-af2d-ea4584da1f9d.png?resizew=170)
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