名校
1 . 如图①,在梯形ABCD中,
,
,
,
,E是AD的中点,O是AC与BE的交点.将
沿BE折起到
的位置,如图②.
![](https://img.xkw.com/dksih/QBM/2022/1/16/2895617408958464/2908474080763904/STEM/80abeb83-67ff-4674-8485-29580473b116.png?resizew=429)
(1)证明:
平面
;
(2)若平面
平面BCDE,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4adf90a8c2b29334cdc5aa5b554991f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4794f2d40733122dbf35a7dd6cf96131.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f121eabff3c62c1a196d9ca5f6f83f0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc11331a7b2d2619b40ee6d34c3bd620.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e742966e3711cfa53dce04022acf4bcc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bcdfe7976bd3f16bfef5c6f1b4f20f23.png)
![](https://img.xkw.com/dksih/QBM/2022/1/16/2895617408958464/2908474080763904/STEM/80abeb83-67ff-4674-8485-29580473b116.png?resizew=429)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97f30533da2e1d2a958dc906c37eba9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1eddaf3f33bd9a99162c061c9dd99aee.png)
(2)若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c44c1843ff6150ebc6aad3e34e477d2d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19fbe81f868cc8270c11ab75ca21bfa8.png)
您最近一年使用:0次
2022-02-03更新
|
1633次组卷
|
4卷引用:北京市中国人民大学附属中学2022届高三2月自主复习检测练习(开学测)数学试题
名校
2 . 如图所示,在四棱锥
中,
底面
,底面
是矩形,
是线段
的中点.已知
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/10/a26e846a-d114-4fab-9ad7-fc7ebc2636e2.png?resizew=162)
(1)求证:
平面
;
(2)求二面角
的余弦值;
(3)直线
上是否存在点
,使得
与
垂直?若存在,求
的长;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a8067cc458cf12887177487c3cfb9c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f4aca5534bce25acaeb7379deed8f8f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/10/a26e846a-d114-4fab-9ad7-fc7ebc2636e2.png?resizew=162)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/373f735f0f04d11f1951eaef1bb78b6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bc46688d8723cf2003fc25890265200.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64785e4401e1d79632e360fd3626ed62.png)
(3)直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
您最近一年使用:0次
2021-03-07更新
|
1194次组卷
|
6卷引用:中国人民大学附属中学2021届高三3月开学检测数学试题
中国人民大学附属中学2021届高三3月开学检测数学试题北京市中国人民大学附属中学2021届高三下学期开学考试数学试题北京交通大学附属中学2024届高三9月开学考数学试题(已下线)专题02 立体几何中存在性问题的向量解法-【重难点突破】2021-2022学年高二数学上册常考题专练(人教A版2019选择性必修第一册)(已下线)专题04 二面角(含探索性问题)-【解题思路培养】2022年高考数学一轮复习解答题拿分秘籍(全国通用版)河北省石家庄市藁城新冀明中学2021-2022学年高二上学期10月考试数学试题
名校
解题方法
3 . 如图,在四棱锥
中,
平面
,四边形
为矩形,
是
的中点,
是
的中点,点
在线段
上且
.
![](https://img.xkw.com/dksih/QBM/2020/3/12/2417993854902272/2418841944547328/STEM/8182ea4baf2843028055858b3a19c23f.png?resizew=324)
(1)证明
平面
;
(2)当
为多大时,在线段
上存在点
使得
平面
且
与平面
所成角为
同时成立?
![](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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fc56c77464a17a1e97b568762a3e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bf4832894665baedfda42021f5430a4.png)
![](https://img.xkw.com/dksih/QBM/2020/3/12/2417993854902272/2418841944547328/STEM/8182ea4baf2843028055858b3a19c23f.png?resizew=324)
(1)证明
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d46cbffebff091d8435b4f17c8710d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09bebb16c0ffc99a945619ae0986cadd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a5f445af1ae136773cb338920552ff2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79a97bb4dcfab4ec7539bc783d563c49.png)
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