如图,直四棱柱
,
,底面
是边长为4的菱形,且
,
为
中点.
![](https://img.xkw.com/dksih/QBM/2020/4/5/2435069797359616/2435691224317952/STEM/bf883ac61bfa41ba824ff9da81301e6f.png?resizew=257)
(1)求证:
平面
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8d927585a17c2e98ef7d5a9589a26ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/71a46dc0bb5d8fa33583817e530a5d21.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://img.xkw.com/dksih/QBM/2020/4/5/2435069797359616/2435691224317952/STEM/bf883ac61bfa41ba824ff9da81301e6f.png?resizew=257)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/662698361c6b3ddaf0c28a3c87be53e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ebb05874eb3353d754af24c9974273e.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d24903da82c11c415b155062561ebda9.png)
更新时间:2020-04-06 16:09:23
|
相似题推荐
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐1】如图,在四棱锥
中,
平面
,
∥
,
,
,
分别是棱
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/93609158-a543-4e16-a1e5-f81b3d3c917b.png?resizew=225)
(1)求证:
∥平面
.
(2)求证:平面
⊥平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5f1897a7e856b42f8cee0f286ad913d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.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/fc3089285ebb92a2cf4f4e52ad59e173.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a16dd8f6cb6a8aadd39ca731febe0ae2.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/93609158-a543-4e16-a1e5-f81b3d3c917b.png?resizew=225)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/212a67f115d1cbe69f100b489babe5f8.png)
(2)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/212a67f115d1cbe69f100b489babe5f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
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【推荐2】如下图所示,在四棱锥
中,底面
是正方形,侧棱
底面
,点E,F分别是
,
上的动点,且
.
平面
;
(2)如果
,PC与底面ABCD所成角的正弦值为
,求平面PAE与平面AED夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.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/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c41158715d94c6c9ffebdee957d2618.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a5f445af1ae136773cb338920552ff2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)如果
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/351f24c3c3f745cb07320d7491916b15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eac97e6740365c85ad857aff85cefbe5.png)
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解答题-问答题
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适中
(0.65)
【推荐1】如图,四边形
是边长为
的菱形,对角线
,F为
的中点,
平面
,
.现沿
将
翻折至
的位置,使得平面
平面
,且点
和E在平面
同侧.
![](https://img.xkw.com/dksih/QBM/2021/4/21/2704440077991936/2717320395513856/STEM/50582396-d77b-4307-bf29-c8d9943cee34.png?resizew=328)
(1)证明:
平面
;
(2)求二面角
大小的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6079f40729551558e7c39a8851f7a67f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7eb3d1070981fed5ca65a34bb2282e6f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44b190c8d3d7d7d0e6e959e8a52eae90.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0761165f1176f3a5fe4f7b052832316d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab2a2834d80ff574e79eae8ca8d4e94f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07c967c9b3f669ea78edd838e1d8b59e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba0fbd88fdb064072eedd136e9cb41ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9dfaad4c4467e27421876d8f2a4371d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://img.xkw.com/dksih/QBM/2021/4/21/2704440077991936/2717320395513856/STEM/50582396-d77b-4307-bf29-c8d9943cee34.png?resizew=328)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5d45c10c00742e89d4123977720c0e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/500df0e782bb081e608f4bc1d576afcf.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ecec1c6a7ac4632c13976db358bcb05e.png)
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解答题-问答题
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适中
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【推荐2】如图,在四棱锥
中,底面
为矩形,
平面
,
,点
,
分别为
,
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/5/bdecfd65-b27f-492e-a364-ab378d4b5161.png?resizew=172)
(1)证明:
平面
.
(2)若
,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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f95475bfc06e884754eb4a455c3f434e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a109c829d652632a88ade6924fcda206.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/2cdba1337ec85fa9722cb4b320a82ae6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63a253c7fdf589ee3dece13d5b5b5732.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/5/bdecfd65-b27f-492e-a364-ab378d4b5161.png?resizew=172)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2b4e753ef119608188c46a50ec597e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b03428a8f91a5674cb8f54766c165f7e.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/585288e61871608f6ff8f7e4a0beafbf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b03428a8f91a5674cb8f54766c165f7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25ab5f5620270e7a9a4218d921325b5b.png)
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【推荐3】已知四面体ABCD,D在面ABC上的射影为
,
为
的外心,
,
.
(1)证明:BC⊥AD;
(2)若E为AD中点,OD=2,求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79faaf0e895a5e3edf40756d990e1161.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef0402dd5ae3db10281f9f1e11738bcb.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/29/5a52cbb1-69b4-4e70-b773-e3b963b6bae7.png?resizew=136)
(1)证明:BC⊥AD;
(2)若E为AD中点,OD=2,求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1ef8395c1f528613bcf683cfe9dc1a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dac901ff434c379e158fccd64dc6401f.png)
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