名校
1 . 在三棱锥
中,
,
平面
,点M是棱
上的动点,点N是棱
上的动点,且
.
![](https://img.xkw.com/dksih/QBM/2024/1/30/3422378703052800/3432026374717440/STEM/d16a09eff99f4f52b2501b3b39b7caac.png?resizew=200)
(1)当
时,求证:
;
(2)当
的长最小时,求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74375e1ba9d3a5d373479874b6634e96.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5f1897a7e856b42f8cee0f286ad913d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdc281ca213b922e5c4bddafd4ef08df.png)
![](https://img.xkw.com/dksih/QBM/2024/1/30/3422378703052800/3432026374717440/STEM/d16a09eff99f4f52b2501b3b39b7caac.png?resizew=200)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d94188fea61c347a150744709920d96e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66fae8e33cd86fa8dab72704eaafe1ba.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1885efcff0b903e314057dd153578600.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70db40c42655327adee01caedfc9d50c.png)
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2024-03-12更新
|
395次组卷
|
6卷引用:浙江省温州市瑞安中学2022-2023学年高二下学期期中数学试题
名校
解题方法
2 . 在如图所示的试验装置中,两个正方形框架ABCD,ABEF的边长都是1,且它们所在的平面互相垂直.活动弹子M,N分别在正方形对角线AC和BF上移动,且CM和BN的长度保持相等,记![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df3b8077a12c488a31a90d4cfcd6456f.png)
.
(2)当MN的长最小时,求平面MNA与平面MNB夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df3b8077a12c488a31a90d4cfcd6456f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59ede160d6012988cec688d057c55168.png)
(2)当MN的长最小时,求平面MNA与平面MNB夹角的余弦值.
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2023-09-29更新
|
211次组卷
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3卷引用:浙江省绍兴市第一中学2023-2024学年高二上学期期中数学试题
3 . 如图,四棱锥
的底面
为直角梯形,平面
平面
,
,
,
,
,
.
(1)若三棱锥
的外接球的球心恰为
中点,求
与平面
所成角的正弦值;
(2)求四棱锥
体积的最大值.
![](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/4cf9a6db3571fa57bfa2d5e4d44c51b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f79863ffcfa63117ca6741b20a48e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080db3af81b29ed10144a1c2e2a4fb8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17bc77b37986d658edad69992c5ea0c8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19fc9f894312e55c87a0d6737080e233.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4994abbead410afe78b1d4e9858aaba.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/28/43afedc7-0414-4fc6-b556-4bdbd81e78b8.png?resizew=127)
(1)若三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
(2)求四棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
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2023-07-27更新
|
997次组卷
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4卷引用:浙江省台州市名校联盟2022-2023学年高二上学期11月五科联赛数学试题
浙江省台州市名校联盟2022-2023学年高二上学期11月五科联赛数学试题重庆市2024届高三上学期9月月度质量检测数学试题(已下线)模块三 专题1 利用空间向量求解探究性问题和最值问题(已下线)专题01 空间向量与立体几何(5)
4 . 如图,已知矩形
中,
,
,其中
为
的中点,将矩形
沿
折成二面角
,且有
.
![](https://img.xkw.com/dksih/QBM/2021/12/18/2875106101248000/2878894919491584/STEM/074e3966-6563-418f-803a-8f03fc829f18.png?resizew=292)
(1)若点
为
的中点,求证
平面
;
(2)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa7aeb2a8d1437eeb4482c3b6ad9f315.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ec91947bd89dda4ca9f74abdb1bd9ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd617e3e225274dccaefee325073ae0d.png)
![](https://img.xkw.com/dksih/QBM/2021/12/18/2875106101248000/2878894919491584/STEM/074e3966-6563-418f-803a-8f03fc829f18.png?resizew=292)
(1)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c597ff77c65c5add6f50294e3eee9536.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a4d3c1df7fcce1d25c44a06a9f168fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2331bccb6ebf5b9fd639df994f575a9.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83c09eec4e14a861af83d7828797d176.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50f59727be34cd56e46ede26aa3c0cf1.png)
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