名校
解题方法
1 . 如图,在三棱柱
中,
,
,四边形
是菱形,
,平面ABB1A1⊥平面ABC,点
是
中点,点
是
上靠近
点的三等分点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/29/0367339c-fbc9-4a69-b811-46dbd0403ca0.jpg?resizew=207)
(1)证明:
;
(2)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/615fc8790237a1b09af51d6bcad6b595.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b10134e7a46e6f6f7cb9d5e2371727d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86cab6037cdd25b50d219550046a37fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/29/0367339c-fbc9-4a69-b811-46dbd0403ca0.jpg?resizew=207)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4b5068a142c39664e25539d27be030b.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e26d9636ad77369535852c6e4493446a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a8035fc825a001d7d9a3dacd8271662.png)
您最近一年使用:0次
2021-06-03更新
|
1553次组卷
|
6卷引用:百师联盟2021届高三冲刺卷(二)新高考卷数学试题
百师联盟2021届高三冲刺卷(二)新高考卷数学试题(已下线)7.5 空间向量求空间角(精讲)-【一隅三反】2022年高考数学一轮复习(新高考地区专用)(已下线)秘籍06 空间向量与立体几何(理)-备战2022年高考数学抢分秘籍(全国通用)(已下线)专题19 空间几何解答题(理科)-1浙江省绍兴市鲁迅中学2022-2023学年高二普通班上学期期末模拟数学试题江西省宜春市宜丰县宜丰中学2022-2023学年高二上学期第三次月考(12月)数学试题
名校
2 . 如图,在四棱锥
中,平面
平面
,
,
,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/2021/5/11/2718627252404224/2719709336920064/STEM/0c75e768-3696-4432-8c6e-1dbc6a71b9b8.png)
(1)求证:
平面
;
(2)求直线
与平面
所成角的正弦值;
(3)在棱
上是否存在点
,使得平面
与平面
所成的锐二面角余弦值为
?若存在,求
的值;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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5732edb0ebc901cc220dca71f96775d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62974d34de3a12418d6b700420afd1b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1134c8e3440abb6cd385af2c169037fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced06b71073e1bb777f326f06016ce17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09d27bd71d79cb19eb554175e4ef0867.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/958330f56d75b05fbf9144e6fd458be4.png)
![](https://img.xkw.com/dksih/QBM/2021/5/11/2718627252404224/2719709336920064/STEM/0c75e768-3696-4432-8c6e-1dbc6a71b9b8.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
(3)在棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f239fbcc58fc15535db4b5084c4f7253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69d048ac0c9b13b54417c2e2de17082b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f32f82942e12701f6ba4b87d02291b1.png)
您最近一年使用:0次
名校
3 . 已知正方形的边长为4,
、
分别为
、
的中点,以
为棱将正方形
折成如图所示的60°的二面角,点
在线段
上.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/16/eeed4286-85b4-4cee-b444-913d2056bcd8.png?resizew=355)
(1)若
为
的中点,且直线
与由
,
,
三点所确定平面的交点为
,试确定点
的位置,并证明直线
平面
;
(2)是否存在点
,使得直线
与平面
所成的角为60°?若存在,求线段
的长,若不存在,请说明理由.
![](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/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.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/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/16/eeed4286-85b4-4cee-b444-913d2056bcd8.png?resizew=355)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/907d5147cea4c9ce855074864fe54506.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](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/a6072ec6dfc0203cabb1fe289a5ddc8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/558ce69401f3c97930f00ba0e2aa6647.png)
(2)是否存在点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/558ce69401f3c97930f00ba0e2aa6647.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d50703c46b6153945d718b198f03b4b5.png)
您最近一年使用:0次
21-22高二上·浙江·期末
名校
4 . 如图,在四棱锥
中,
,面
面
,M为
的中点.
![](https://img.xkw.com/dksih/QBM/2021/5/6/2715478096633856/2715717048090624/STEM/d76f136a01df41fc8528567427fa3c21.png?resizew=188)
(Ⅰ)求证:
;
(Ⅱ)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80c753cb1eb73fd8d136d00462970797.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9abd98da18aa05708c279a0fabcbc6f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3abb27f8d654064a92f9d7a11e586ab5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ee10bfa63ab58c5027bc0af0c0d016f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccaee8f228ff24e7c89879bb5b999cf2.png)
![](https://img.xkw.com/dksih/QBM/2021/5/6/2715478096633856/2715717048090624/STEM/d76f136a01df41fc8528567427fa3c21.png?resizew=188)
(Ⅰ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7aaccd4f94fac8096a6cf70d94eb589.png)
(Ⅱ)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15a424b50eaeafa6f302ffd95476cb86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/500df0e782bb081e608f4bc1d576afcf.png)
您最近一年使用:0次
2021-05-07更新
|
2547次组卷
|
6卷引用:广西南宁市第三中学2021届高三二模数学(理)试题
广西南宁市第三中学2021届高三二模数学(理)试题陕西省汉中市2022届高三上学期第一次教学质量检测理科数学试题陕西省汉中市2022届高三教学质量第一次检测考试理科数学试题(已下线)【新东方】高中数学20210429—002【2020】【高二上】(已下线)专题05 空间向量与立体几何(重点)-2020-2021学年高二数学下学期期末专项复习(北师大版2019选择性必修第一册、第二册)(已下线)专题01 空间向量与立体几何的典型题(一)-【尖子生专用】2021-2022学年高二数学考点培优训练(人教A版2019选择性必修第一册)
名校
解题方法
5 . 如图,在三棱柱
中,
平面
分别为
的中点,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc9b17d5fe8e039d5de1f195b7202778.png)
![](https://img.xkw.com/dksih/QBM/2021/4/22/2705354688331776/2713098799767552/STEM/5067447b-2f9c-4cdc-867c-7f985c8bfbd3.png?resizew=226)
(1)求证:
平面
;
(2)求二面角
的正弦值;
(3)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a8bfe2553e852df73185d017c0a62fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be8e413b6b062029ec08a51ba604b5fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2efe30b0b1a3b0c49b4fa58b7cce943b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc9b17d5fe8e039d5de1f195b7202778.png)
![](https://img.xkw.com/dksih/QBM/2021/4/22/2705354688331776/2713098799767552/STEM/5067447b-2f9c-4cdc-867c-7f985c8bfbd3.png?resizew=226)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e56fdf217165748fafe938b64fa08179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87c0bfeadcf17b2a45896071f07a4a5a.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e59b1f7689bff6644bfdeb9e36feb163.png)
(3)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c63e36329f5e0979f5ee776ac5d06327.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
您最近一年使用:0次
2021-05-03更新
|
1593次组卷
|
3卷引用:天津市河西区2021届高三下学期总复习质量调查(二)数学试题
6 . 如图,在四棱锥
中,底面
为正方形,
底面
为线段
的中点,
为线段
上的动点.
![](https://img.xkw.com/dksih/QBM/2021/4/25/2707316694630400/2712544203808768/STEM/0dc589e6-1f40-411d-89dd-a0e505ba98c4.png?resizew=218)
(1)证明
;
(2)当
为线段
的中点时,求直线
与平面
所成角的正弦值.
![](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/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dfaefb10f82b89802bb420b3c41de1bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b6ff342277250410a6e35cddbc66a83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://img.xkw.com/dksih/QBM/2021/4/25/2707316694630400/2712544203808768/STEM/0dc589e6-1f40-411d-89dd-a0e505ba98c4.png?resizew=218)
(1)证明
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/519b51860ce9066e3a4807a7b7cdf58b.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/881129039cb98be128af55ffa1d3b7dc.png)
您最近一年使用:0次
名校
7 . 如图,在四棱锥
中,
平面
,底面
是直角梯形,其中
,
,
,
,E为棱
上的点,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/19/539de07f-0b4b-4cc1-9bcd-10da86d0f8a4.png?resizew=154)
(1)若F为棱
的中点,求证:
平面
;
(2)(i)求证
平面
;
(ii)设Q为棱
上的点(不与C,P重合),且直线
与平面
所成角的正弦值为
,求
的值.
![](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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f571396be1aa4a8914a66f7d7abd6381.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1134c8e3440abb6cd385af2c169037fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abfb2735e1683a6ae86b5b97a0032e4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00bab2c27eac56fffa4cd7dbe1dcdf1a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b41744ec71119e7264ef9673a35805a8.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/19/539de07f-0b4b-4cc1-9bcd-10da86d0f8a4.png?resizew=154)
(1)若F为棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57f9d682e5d3cc8573574d8d11636758.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
(2)(i)求证
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8d2d217e9bcd059908f117dfc4d4259.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
(ii)设Q为棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63a253c7fdf589ee3dece13d5b5b5732.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf3d566704b44ea4ef1f99c37bd46902.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dee14db57f0c762aad845cf5b4a243c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2942447b6af4f2749668439d5ee03a7.png)
您最近一年使用:0次
2021-04-11更新
|
1100次组卷
|
4卷引用:天津市耀华中学2022届高三暑假线上调研数学试题
天津市耀华中学2022届高三暑假线上调研数学试题(已下线)一轮复习大题专练50—立体几何(线面角2)—2022届高三数学一轮复习北京市清华大学附属中学2020-2021学年高二上学期期末考试数学试题(已下线)专题02 空间向量与立体几何的典型题(二)-【尖子生专用】2021-2022学年高二数学考点培优训练(人教A版2019选择性必修第一册)
解题方法
8 . 如图,在三棱锥
中,
底面
.点D,E,N分别为棱
的中点,M是线段
的中点,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/29/4a950e55-c57f-47d5-8d2c-ea4312f94609.png?resizew=201)
(Ⅰ)求证:
平面
;
(Ⅱ)求二面角
的正弦值;
(Ⅲ)已知点H在棱
上,且直线
与直线
所成角的余弦值为
,求线段
的长.
![](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/a9177a42f9ab232822de2b889a572932.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55928df632fc6f2b88a44afe37e5a4e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/119d2453d9262756ef3be3b4b52a762c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/29/4a950e55-c57f-47d5-8d2c-ea4312f94609.png?resizew=201)
(Ⅰ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edcf19a7f0dd0cdf59516ae585025110.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
(Ⅱ)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3f1c2d75dc63c9669f3b7b0e1a2ff4.png)
(Ⅲ)已知点H在棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff9d2abf13c2842f58654abf73c6b4ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b94ab384ee86aed107af8b3bbb1d13b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/826c728050e3378921442ace20269ef6.png)
您最近一年使用:0次
9 . 如图,在多面体
中,已知
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/31/bb7f1131-ba85-4755-8bf7-60d07be4da93.png?resizew=177)
(1)求证:
平面
;
(2)若
,求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9142a8490de14a87eda628ffa7e28982.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96398993706ec5da6576bc7e6168417a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9439a0ae5bc0df651cf68ff9558a0421.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/31/bb7f1131-ba85-4755-8bf7-60d07be4da93.png?resizew=177)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97f30533da2e1d2a958dc906c37eba9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c09afc70f448545336304333d5b5658b.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07c51707d83a3b7508f05b0605026923.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
您最近一年使用:0次
名校
解题方法
10 . 如图所示,在四棱台
中,
底面
,四边形
为菱形,
,
.
![](https://img.xkw.com/dksih/QBM/2021/3/15/2678680104845312/2684215312261120/STEM/1561cd34-00ff-46d2-9f21-7959cb76d236.png?resizew=248)
(1)若
为
中点.求证:
平面
;
(2)求直线
与平面
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5845ccc0d735dc14c92a8926d9b1def6.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/9eee296a7d9fba487f1485c61580196f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/293cdfa41786bfd10ac7a4e92769dab0.png)
![](https://img.xkw.com/dksih/QBM/2021/3/15/2678680104845312/2684215312261120/STEM/1561cd34-00ff-46d2-9f21-7959cb76d236.png?resizew=248)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d0edb1508fc95765f3bb316bcb5252d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9edc50f7febbc2d5d8dcdc23a3630a7.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22adbc0da438220f9cace11b629d799b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7935fe3125f247b7bea4f065ce9ad985.png)
您最近一年使用:0次