名校
1 . 如图,在三棱锥
中,
底面
,
.点
、
、
分别为棱
、
、
的中点,
是线段
的中点,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/15/a113988e-a7ec-4d54-864b-7ce976499647.png?resizew=205)
(1)求证:
平面
;
(2)求平面
与平面
夹角的正弦值;
(3)点
在棱
上,直线
与
所成角余弦值为
,求线段
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/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f8e9ec412ea0355e4e5cd06c60e5fee.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/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/487b14c446e989c68d0e148cc557dbf2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/15/a113988e-a7ec-4d54-864b-7ce976499647.png?resizew=205)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7592c4f01c8e06c7ee90df5b9413a9f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0701f67727b0fc8100cfb5e20ec27d9b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6221be113e161825e54d48a2fb16d516.png)
(3)点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](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/8e468f168f3657d84d44be5eb89a62d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/826c728050e3378921442ace20269ef6.png)
您最近一年使用:0次
2023-01-12更新
|
695次组卷
|
8卷引用:重庆市永川景圣中学校2021-2022学年高二上学期第一次月考数学试题
重庆市永川景圣中学校2021-2022学年高二上学期第一次月考数学试题北京八中2021届高三上学期期中数学试题(已下线)专题37 合理建系-妙解三类空间角问题-备战2022年高考数学一轮复习一网打尽之重点难点突破天津市静海区瀛海学校2021-2022学年高二上学期第一次质量检测数学试题(已下线)专题20 立体几何综合大题必刷100题-【千题百练】2022年新高考数学高频考点+题型专项千题百练(新高考适用)(已下线)第08讲 第七章 立体几何与空间向量(基础拿分卷)天津市北京师范大学天津附属中学2022-2023学年高三上学期期末数学试题江苏省淮安市洪泽湖高级中学2022-2023学年高二下学期第一次月考数学试题
解题方法
2 . 如图,在正方体
中,
是
的中点,
,
,
分别是
,
,
的中点,求证:
![](https://img.xkw.com/dksih/QBM/2022/5/8/2974933547376640/2979080373813248/STEM/e0efe439-5142-4d5a-b7ac-d28a804ac5a0.png?resizew=200)
(1)直线
平面
;
(2)
为线段
上一点,且
,求证:
平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cfbc0b5a8fbde804bd8425a4b76d207.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/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c2bc5e50b8dfa02601c70822252854a.png)
![](https://img.xkw.com/dksih/QBM/2022/5/8/2974933547376640/2979080373813248/STEM/e0efe439-5142-4d5a-b7ac-d28a804ac5a0.png?resizew=200)
(1)直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f31d54d125c042169e282f14eddd45a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2bf9ef324f1289e205e29fed105c38e.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22adbc0da438220f9cace11b629d799b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7f9d6c4583b60e2ece705889264f0f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63e82b3e225741b7f541fb6cff225d52.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ffe8a84ca3a13f82aff1a022edc66065.png)
您最近一年使用:0次
2022-05-14更新
|
1496次组卷
|
6卷引用:广东省惠州一中、珠海一中、中山纪念中学2021-2022学年高一下学期第二次段考数学试题
广东省惠州一中、珠海一中、中山纪念中学2021-2022学年高一下学期第二次段考数学试题(已下线)第11练 空间直线、平面的平行-2022年【暑假分层作业】高一数学(人教A版2019必修第二册)(已下线)空间直线、平面的平行(已下线)专题08 空间直线与平面的平行问题(1)-期中期末考点大串讲广东省深圳实验学校2021-2022学年高一下学期期中数学试题广东省2024年普通高中学业水平合格性考试考前冲刺数学试题二
名校
3 . 如图,正方形
与梯形
所在平面互相垂直,已知
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/10/a1be42ea-8536-41de-9afc-b376532d40ef.png?resizew=227)
(1)求证:
平面
.
(2)求平面
与平面
夹角的余弦值
(3)线段
上是否存在点
,使平面
平面
?若存在,求出
的值;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ecc1cb55a57dde481f8dd07ab150676.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f79863ffcfa63117ca6741b20a48e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdb2dd10731b99c0f4f89ee957f8a239.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32ae5f8381ffcce4281a0ca817b82a41.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/10/a1be42ea-8536-41de-9afc-b376532d40ef.png?resizew=227)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9d32e76582bf550593fdef53e081225.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10fc7991ea17d54ff5f4445ac5699463.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ae8768996ca9a0f2c5d9a19abbd54df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10fc7991ea17d54ff5f4445ac5699463.png)
(3)线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fc56c77464a17a1e97b568762a3e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa7084fef1f20c7af36659c1faa643ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ae8768996ca9a0f2c5d9a19abbd54df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cada49bc5cf1cf8615eaf91863d18535.png)
您最近一年使用:0次
2022-07-08更新
|
1404次组卷
|
4卷引用:北京市第二中学2020-2021学年高二下学期期末数学试题
北京市第二中学2020-2021学年高二下学期期末数学试题(已下线)第06讲 向量法求空间角(含探索性问题) (高频考点—精练)辽宁省鞍山市普通高中2022-2023学年高二上学期第三次月考数学(B卷)试题辽宁省鞍山市海城市牛庄高级中学等二校2022-2023学年高二上学期10月月考数学试题
名校
4 . 如图,在四棱锥
中,
平面
,且四边形
是正方形,
,
,
分别是棱
,
,
的中点.
(1)求证:
平面
;
(2)若
,求异面直线
与
所成角的余弦值.
![](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/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/1/5919d754-23c3-475f-bfe1-cef023d94af1.png?resizew=177)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8bc5d8308a060d6068cfc9f69fe79e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24dc8826770249f3996b8a188c03da92.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9bc1ff15476200a46875dc1f61ba53c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e61620a272dada8d4b9a9fab6379dfd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c4eccda4edcee29a5f15609e85106df.png)
您最近一年使用:0次
2024高三·全国·专题练习
解题方法
5 . 如图,在三棱柱
中,侧面
是矩形,侧面
是菱形,
,
、
分别为棱
、
的中点,
为线段
的中点.证明:
平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ac61c24f99a4e466f1e2ea011893866.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58cc6184b191e6da43911e701121517e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb5a97c6b563f00d0a71aef901eb7277.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/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56f7ba05c54b3de1f4378f7c8eb58328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e516121599c9fcc528121c00afcf52fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dcafa398cc6b6079883e7ad153eb62d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/657dffbd3623b705f871878fbd9df57e.png)
您最近一年使用:0次
2023-11-12更新
|
674次组卷
|
7卷引用:第03讲 直线、平面平行的判定与性质(八大题型)(讲义)
(已下线)第03讲 直线、平面平行的判定与性质(八大题型)(讲义)(已下线)第10讲 8.5.3 平面与平面平行-【帮课堂】(人教A版2019必修第二册)(已下线)13.2.3 直线与平面的位置关系(1)-【帮课堂】(苏教版2019必修第二册)(已下线)11.3.3平面与平面平行-同步精品课堂(人教B版2019必修第四册)(已下线)专题3.5空间直线、平面的平行-重难点突破及混淆易错规避(人教A版2019必修第二册)(已下线)8.5.3 平面与平面平行-同步精品课堂(人教A版2019必修第二册)(已下线)11.3.3 平面与平面平行-【帮课堂】(人教B版2019必修第四册)
6 . 如图,以正方形
的边
所在直线为旋转轴,其余三边旋转120°形成的面围成一个几何体
.设
是
上的一点,
,
分别为线段
,
的中点.
平面
;
(2)若
,求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02cfa6b4db3a67fcd3c169fd8502a66d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4193fb98c610f41f9a6c89d046f13d32.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/500df0e782bb081e608f4bc1d576afcf.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59fb768fc63e1aabddbfb2b3e7c5b51a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e4d775e9fb8bca58a25e75d5b21b05f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f57043f1d131e9c7c8b71bf8a68bacbc.png)
您最近一年使用:0次
名校
解题方法
7 . 如图,在四棱锥
中,底面
是矩形.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/13/fdb48697-d46f-452c-85a1-a75595d32731.png?resizew=199)
(1)设
为
上靠近
的三等分点,
为
上靠近
的三等分点.求证:
平面
.
(2)设
是
上靠近点
的一个三等分点,试问:在
上是否存在一点
,使
平面
成立?若存在,请予以证明;若不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06a5faf3cbb633fc4294c8ce703c64c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/13/fdb48697-d46f-452c-85a1-a75595d32731.png?resizew=199)
(1)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef4113c492885ba7c47fe42ac792578f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](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/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edcf19a7f0dd0cdf59516ae585025110.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3201d3796ed9a29338aac25245a7c8e2.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/683c590673eece14fea3319c4fd5eb55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/683c590673eece14fea3319c4fd5eb55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c8ccd4181f956f6e0140bf0ab8f0716.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c66d99a6a8415ddad22bbed33b64cfb.png)
您最近一年使用:0次
2021-05-08更新
|
2328次组卷
|
4卷引用:吉林省东北师大附属中学2020-2021学年高一下学期期中考试数学试题
吉林省东北师大附属中学2020-2021学年高一下学期期中考试数学试题(已下线)专题23 立体几何中平行的存在性问题-【重难点突破】2021-2022学年高一数学常考题专练(人教A版2019必修第二册)(已下线)第03讲 空间直线、平面的平行 (高频考点—精练)江苏省连云港市赣榆第一中学2020-2021学年高一下学期第二次月考数学试题
解题方法
8 . 如图,在几何体
中,菱形
所在的平面与矩形
所在的平面互相垂直.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/28/ac1aeb1a-876f-4068-97b4-b4c4e18f5870.png?resizew=174)
(1)若
为线段
上的一个动点,证明:
∥平面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9a32bd7a1b78b5a0ec562c4025aea8c.png)
(2)若
,
,直线
与平面
所成角的正弦值为
,求点
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9165d9bfbb0f0d19eb482c2a4c1b29b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f84f169e50dc59d4f7a8e1e36f5c847.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/28/ac1aeb1a-876f-4068-97b4-b4c4e18f5870.png?resizew=174)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db54223bb3fc2fe2497213a4d1f94827.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9a32bd7a1b78b5a0ec562c4025aea8c.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f945a69cf7e8213e50622125cde652f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/500df0e782bb081e608f4bc1d576afcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2f75c42c77264076166fff76cfab4ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/500df0e782bb081e608f4bc1d576afcf.png)
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9 . 如图,在四棱锥
中,
,
,点P是以AB为直径的半圆上的一点(不同于A,B两点),平面
平面ABCD,E,F分别为线段AD,PC的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/19/24d99452-876e-4535-ad8e-fd0e9f913157.png?resizew=161)
(1)求证:
平面PAB;
(2)当四棱锥
的体积最大时,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f79863ffcfa63117ca6741b20a48e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/899f82187d0591696c36ff4bbf74070d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/19/24d99452-876e-4535-ad8e-fd0e9f913157.png?resizew=161)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06222ee533c2484ab25321a6abbf98cb.png)
(2)当四棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08b0dc4f92cba842f44477bc9811065c.png)
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名校
解题方法
10 . 如图,四棱锥
中,
是等边三角形,底面
是直角梯形,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9bfa68259d7a331be323b2038d628a.png)
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2234205f80829a5bbc6ae3a675fe4f85.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/645c2acbf5a03068cba4d6dff6563976.png)
,
,
分别是
的中点.
![](https://img.xkw.com/dksih/QBM/2021/12/11/2870313655083008/2875145049554944/STEM/7aa1701bd041479fa2643d9c8faf3b4e.png?resizew=266)
(1)求证:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c63e36329f5e0979f5ee776ac5d06327.png)
平面
;
(2)若
,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/2205cffebf8c4d5f81d15ed7b85c8936.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9bfa68259d7a331be323b2038d628a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2234205f80829a5bbc6ae3a675fe4f85.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/645c2acbf5a03068cba4d6dff6563976.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b96fac11d72f72c805dbddb8da72d68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62794ea73abc2a84aa0512c5b205eb12.png)
![](https://img.xkw.com/dksih/QBM/2021/12/11/2870313655083008/2875145049554944/STEM/7aa1701bd041479fa2643d9c8faf3b4e.png?resizew=266)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c63e36329f5e0979f5ee776ac5d06327.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9bfa68259d7a331be323b2038d628a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be41b05e11ba5eadaaed9a224b949774.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c63e36329f5e0979f5ee776ac5d06327.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
您最近一年使用:0次