解题方法
1 . 如图,棱柱
的所有棱长都等于2,且
,平面
平面
.
与平面
所成角的余弦值;
(2)在棱
所在直线上是否存在点P,使得
平面
.若存在,求出点P的位置;若不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d093bd9b62f186878323745997fb0f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0671b4776e142e17a79af5b3f0378ef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e69ddcbb370ad11e073881f52834b6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c05f5452f7682e52db629a28becb116.png)
(2)在棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f92ff089ec8ff211a9fcefe4682c0618.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cee3d1518e197f7f25c341da6b1e3483.png)
您最近一年使用:0次
2024-04-17更新
|
1375次组卷
|
2卷引用:2024年东北三省高考模拟数学试题(一)
2024·全国·模拟预测
解题方法
2 . 如图①,在直角梯形
中,
,
,
,
,
,
,
分别在边
上,四边形
为正方形,将
沿着边
旋转,使得
,如图②.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/29/20bf03eb-c5aa-47b8-af18-42755b8c370e.png?resizew=330)
(1)求证:
平面
;
(2)
是棱
的中点,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9186e4574ffe28e673724fcb019db208.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/424269ceef173843aae76e39ecdf6111.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33804bda15aa245e3a64dcc2e4c0b24f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d70dc2c20619a4fc12a0cfda59af5b69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97bb57534d77c2355aef18c9105c189d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19d8b64ae5ebb831b1d03316e89f4aaa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e96f3af5833b0cab2dff3e615c8790ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a618e2fa885d453e050c21bc05f8fed4.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/29/20bf03eb-c5aa-47b8-af18-42755b8c370e.png?resizew=330)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a5f445af1ae136773cb338920552ff2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fa7bbd7831e9ff4f8cffc8889d34f05.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43ab0137fe07fc29af8eae62bb8a8495.png)
您最近一年使用:0次
名校
解题方法
3 . 如图所示,在四棱锥
中,底面
为直角梯形,
∥
、
、
、
,
、
分别为
、
的中点,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/27/8372c1fd-7a2e-46d0-82d4-828a5e99b5da.png?resizew=184)
(1)证明:平面
平面
;
(2)若
与
所成角为
,求二面角
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/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90ff6d7dd48b57f03d82d2c522ee9b94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/639bec6242a4b3f7bfb4b7033a67328c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62974d34de3a12418d6b700420afd1b2.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/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9829fc6685b59fdc609f32f30ebd9e6d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/27/8372c1fd-7a2e-46d0-82d4-828a5e99b5da.png?resizew=184)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1e5fa72f2878b476bc57f0df12d6555.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a590bdfe296689fc138d8995deae2026.png)
您最近一年使用:0次
2023-11-05更新
|
2713次组卷
|
13卷引用:广东省广州市奥林匹克中学2021-2022学年高二下学期6月月考数学试题
广东省广州市奥林匹克中学2021-2022学年高二下学期6月月考数学试题辽宁省铁岭市昌图县第一高级中学2021-2022学年高一下学期期末数学试题(已下线)1.2.4 二面角(已下线)第4讲 空间向量的应用 (3)(已下线)第07讲 空间向量的应用 (2)山西省运城市稷山县稷山中学2023-2024学年高二上学期11月月考数学试题重庆市北碚区缙云教育联盟2024届高考零诊数学试题(已下线)四川省成都市第七中学2023-2024学年高二上学期12月月考数学试题北京市丰台区2023-2024学年高二上学期期末模拟数学试题江西省上饶市广丰区南山中学2023-2024学年高二上学期期末模拟数学试题河南省郑州市第十八中学2023-2024学年高二上学期期末模拟数学试题(三)新疆克拉玛依市2022届高三下学期第三次模拟检测数学(理)试题新疆维吾尔自治区阿克苏地库车市第二中学2023-2024学年高二上学期第二次月考(12月)数学
名校
4 . 如图,直三棱柱
中,
是边长为
的正三角形,
为
的中点.
![](https://img.xkw.com/dksih/QBM/2022/7/6/3016722249293824/3017456663756800/STEM/3a614c5d3a794139bd5167c0674181c9.png?resizew=208)
(1)证明:
平面
;
(2)若直线
与平面
所成的角的正切值为
,求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/2022/7/6/3016722249293824/3017456663756800/STEM/3a614c5d3a794139bd5167c0674181c9.png?resizew=208)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eeebdf3d00c146a1b4d220909d7573c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7f6f93171329d508d491143b9d71f7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83303d3784492506fc44f2b4d6b07bc1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9539f8fb13345b449274b67bbda995db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea848cd2aa3a464618020475097949fc.png)
您最近一年使用:0次
2022-07-07更新
|
2917次组卷
|
13卷引用:湖南省郴州市2021-2022学年高二下学期期末数学试题
湖南省郴州市2021-2022学年高二下学期期末数学试题河北省保定市唐县第一中学2022-2023学年高二上学期期中考试数学试题(已下线)第一章 空间向量与立体几何(基础、典型、新文化、压轴)分类专项训练-2022-2023学年高二数学考试满分全攻略(人教A版2019选择性必修第一册)河南省濮阳市2023-2024学年高二上学期9月大联考数学试题重庆市万州沙河中学2023-2024学年高二上学期10月月考数学试题陕西省西安市长安区2023-2024学年高二上学期10月月考数学试题山东省济南第一中学2023-2024学年高二上学期10月月考数学试题河南省信阳市第二高级中学2023-2024学年高二上学期第二次阶段测试数学试题山西省吕梁市柳林县鑫飞中学2023-2024学年高三上学期学情调研质量检测数学模拟试卷云南省楚雄实验中学2023届高三上学期12月月考数学试题山东省枣庄市第八中学2023-2024学年高二上学期10月月考数学试题贵州省思南民族中学2023-2024学年高二上学期数学期中模拟试题(B)贵州省都匀兴华中学2023-2024学年高二上学期阶段测试(一)数学试题
名校
5 . 在圆锥PO中,高
,母线
,B为底面圆O上异于A的任意一点.
![](https://img.xkw.com/dksih/QBM/2022/4/14/2958094116044800/2959245912768512/STEM/910e6a9c-8820-46c4-b2b2-9fcbf48d850f.png?resizew=389)
(1)当
时,过底面圆心O作
所在平面的垂线,垂足为H,求证:
;
(2)当
时,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae890f9e8b32aa53a54158f24f4a87bc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00bab2c27eac56fffa4cd7dbe1dcdf1a.png)
![](https://img.xkw.com/dksih/QBM/2022/4/14/2958094116044800/2959245912768512/STEM/910e6a9c-8820-46c4-b2b2-9fcbf48d850f.png?resizew=389)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3825ccc273ef9a672a606432d165b866.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2205cffebf8c4d5f81d15ed7b85c8936.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25490c72ad1b9968e6be5c5f6b268ab3.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d162c29b1e484cfc87350dd68f00b85.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb92d6ab1b9a520e272f3649f35ab07a.png)
您最近一年使用:0次
2022-04-16更新
|
1832次组卷
|
5卷引用: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)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)回归教材重难点03 空间向量与立体几何-【查漏补缺】2022年高考数学(理)三轮冲刺过关甘肃省2022届高三第二次高考诊断考试数学(理)试题吉林省白山市抚松县第一中学2023届高考模拟预测数学试题宁夏回族自治区固原市西吉中学2024届高三上学期第五次模拟考试数学(理)试题
解题方法
6 . 如图,在三棱锥D—ABC中,G是△ABC的重心,E,F分别在BC,CD上,且
,
.
![](https://img.xkw.com/dksih/QBM/2022/3/16/2937568463167488/2938680845516800/STEM/a9bb2de0d4534065ba668f42fc8fe81c.png?resizew=181)
(1)证明:平面
平面ABD;
(2)若
平面ABC,
,
,
,P是线段EF上一点,当线段GP长度取最小值时,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91928fb7fc49b70ffd1f3a7dbeb566f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47ad6b6519a55c2a502b9a94d3b514b4.png)
![](https://img.xkw.com/dksih/QBM/2022/3/16/2937568463167488/2938680845516800/STEM/a9bb2de0d4534065ba668f42fc8fe81c.png?resizew=181)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51daddc16eddbdf70ab3c15a28f6286b.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97f30533da2e1d2a958dc906c37eba9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080db3af81b29ed10144a1c2e2a4fb8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d2873cc55831ef240c0e172cf89ae29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa7aeb2a8d1437eeb4482c3b6ad9f315.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d399d731913a563e291b817831a0c678.png)
您最近一年使用:0次
名校
7 . 如图,四边形
是正方形,
平面
,
,
,
,F为
的中点.
![](https://img.xkw.com/dksih/QBM/2022/3/10/2933351405576192/2938037186764800/STEM/ea88ee5151bd4014a6200ea5a6021887.png?resizew=174)
(1)求证:
平面
;
(2)求二面角
的大小.
![](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/85ff59abe5e0a0f35141a78e63da7579.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82465b63174087aeba7788ed984583d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07dd741bc3f02d8552afbcf63fba4fb6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://img.xkw.com/dksih/QBM/2022/3/10/2933351405576192/2938037186764800/STEM/ea88ee5151bd4014a6200ea5a6021887.png?resizew=174)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f306ff6d237cd9d847aa109acf9333d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bf12905647aeeded72bbca21a63f319.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/729a3ac9d8a312996c1aa9eb2e1959fa.png)
您最近一年使用:0次
2022-03-17更新
|
2678次组卷
|
6卷引用:湖北省黄冈市罗田县第一中学2021-2022学年高二实验班下学期3月月考数学试题
名校
8 . 如图,四边形ABCD为梯形,
,
,
,点
在线段
上,且
.现将
沿
翻折到
的位置,使得
.
![](https://img.xkw.com/dksih/QBM/2022/3/2/2927482149060608/2936643822362624/STEM/f93ceca9-e75b-4c76-b3e0-ff9295997956.png?resizew=251)
(1)证明:
;
(2)点
是线段
上的一点(不包含端点),是否存在点
,使得二面角
的余弦值为
?若存在,则求出
;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10df84d553a8826a7ce9bff4bf0d95b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/998329f9cdb86f5d60d7d5d70fc3781e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86752e4373797b2231f76b074cbf75d0.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/9b937442ad4cc480adc11bb143559454.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dbe40405cd7bd60d69dd535d6da85c00.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6fbb42439079fa563100decbad833e10.png)
![](https://img.xkw.com/dksih/QBM/2022/3/2/2927482149060608/2936643822362624/STEM/f93ceca9-e75b-4c76-b3e0-ff9295997956.png?resizew=251)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fbfbaf73297240eb116f22489519895a.png)
(2)点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc5adb5eb60ae4435a12d93854066298.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98553247801c03de24cf7e687016e655.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1174142f3bba761585b6bc2653009b36.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad0d6d600e2676abc87e05cde8aebc1a.png)
您最近一年使用:0次
2022-03-15更新
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3282次组卷
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9卷引用:2022届全国新高考Ⅱ卷仿真模拟数学试卷(六)
名校
9 . 在四棱锥
中,
,
,
,
,
为正三角形,且平面
平面ABCD.
![](https://img.xkw.com/dksih/QBM/2022/1/14/2894422649323520/2897144021975040/STEM/68d32b3d-3e68-4d14-a0a8-b707d27d9339.png?resizew=192)
(1)求二面角
的余弦值;
(2)线段PB上是否存在一点M(不含端点),使得异面直线DM和PE所成的角的余弦值为
?若存在,指出点M的位置;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/b0fff774b4b0087a6f304ce930d359be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4622847599656e5684350af7e60f0d20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea4f5eec0addba78f2e0cdfb7ecc59a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c45087cde2d66377517a3fce5553b35.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55a675310c8ba418e5a59beb7317e21e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://img.xkw.com/dksih/QBM/2022/1/14/2894422649323520/2897144021975040/STEM/68d32b3d-3e68-4d14-a0a8-b707d27d9339.png?resizew=192)
(1)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df6aaed07f0b69eee41de11613fc74de.png)
(2)线段PB上是否存在一点M(不含端点),使得异面直线DM和PE所成的角的余弦值为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaa42621cd6793e7f3673fdb49bc3123.png)
您最近一年使用:0次
2022-01-18更新
|
2096次组卷
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4卷引用:内蒙古包头市2021-2022学年高二上学期期末考试数学(理)试题
内蒙古包头市2021-2022学年高二上学期期末考试数学(理)试题内蒙古呼和浩特市新城区呼市十四中学2023-2024学年高二上学期期中数学试题(已下线)专题03 空间向量求角度与距离10种题型归类-【巅峰课堂】2023-2024学年高二数学上学期期中期末复习讲练测(人教A版2019选择性必修第一册)(已下线)江苏省南通市如皋市2021-2022学年高二下学期期初调研数学试题
名校
10 . 如图,直四棱柱
的底面
是平行四边形,
,
,
,点
是
的中点,点
在
且
.
![](https://img.xkw.com/dksih/QBM/2021/11/5/2844863191736320/2849768661663744/STEM/62d467d7444646de9f5ca0bde29f4346.png?resizew=265)
(1)证明:
平面
;
(2)求锐二面角
平面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c4cb73e9d976cbfe9c590044fa69dd5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4339a40ae9d1947ec3a4b3e2fa3a16cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9c3ec174b1ce835cc8737ff6ce57e52.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f66fb71b75b63594ebeeeebd1963eed5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56f7ba05c54b3de1f4378f7c8eb58328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4272ca39f8f4d12bcbc4a0bc50e8f001.png)
![](https://img.xkw.com/dksih/QBM/2021/11/5/2844863191736320/2849768661663744/STEM/62d467d7444646de9f5ca0bde29f4346.png?resizew=265)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d1d2e0f281222a5f289ea4008370aed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a681d311a864d38cf306a0c137cbcca.png)
(2)求锐二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6238a6fb52a9d2e3521ba66ef9a5c247.png)
您最近一年使用:0次