名校
1 . 如图,在四棱锥
中,
平面
,
,
,
,
,
是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/31/7203f6aa-48c3-45a7-9a64-75981edc4e4f.png?resizew=171)
(1)证明:平面
平面
;
(2)已知二面角
的平面角的余弦为
,求
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/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f8eeeea1c9652cacce976f8129cf520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ecf7679c8b4b1e442ce4286d4b0e9c32.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d47dff1b9d37e2b2cb2afe4bd0c4c04f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/31/7203f6aa-48c3-45a7-9a64-75981edc4e4f.png?resizew=171)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/342d452a7b850cd3a15b23619ad39bd7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e6c2dad46a9052a4185a4f7b4ae8a2e.png)
(2)已知二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1636b4530c0b42d0e0b649e90e3b9e85.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf31876698721a199c7c53c6b320aa86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e6c2dad46a9052a4185a4f7b4ae8a2e.png)
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2021-07-21更新
|
1114次组卷
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3卷引用:江西省南昌市豫章中学2021-2022学年高二上学期入学调研(A)数学(理)试题
名校
解题方法
2 . 正方体
棱长为3,点E在边BC上,且满足BE=2EC,动点M在正方体表面上运动,并且总保持
,则动点M的轨迹的周长为__ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/652bdad4583eea2756d6441fc89eb797.png)
您最近一年使用:0次
2022-02-25更新
|
603次组卷
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6卷引用:江西省南昌市洪都中学2019-2020学年高二上学期第三次联考理数试题
江西省南昌市洪都中学2019-2020学年高二上学期第三次联考理数试题江西省赣州市赣县中学北校区2019-2020学年高二上学期月考数学(文)试题江西省赣州市赣县中学北校区2019-2020学年高二上学期月考数学(理)试题四川省叙永第一中学校2022届高三第一次诊断性考试模拟题数学文科试题(一)(已下线)专题18 空间几何题综合问题(体积、面积、角度、距离、轨迹等)(选填题)-1(已下线)考点14 立体几何中的动态问题 2024届高考数学考点总动员【练】
名校
3 . 如图,在四棱锥
中,等边三角形PAD所在的平面与正方形ABCD所在的平面互相垂直,O为AD的中点,E为DC的中点,且
.
![](https://img.xkw.com/dksih/QBM/2021/2/1/2648571756912640/2651466019438592/STEM/d17505d840ed47e1b37add8942f4e808.png?resizew=265)
(1)求证:
平面ABCD;
(2)求二面角
的平面角的余弦值;
(3)在线段AB上是否存在点M,使直线PM与
所在平面成
角?若存在,求出AM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/09d27bd71d79cb19eb554175e4ef0867.png)
![](https://img.xkw.com/dksih/QBM/2021/2/1/2648571756912640/2651466019438592/STEM/d17505d840ed47e1b37add8942f4e808.png?resizew=265)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3e126c16032892966489053f44b9048.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64cc21c59d53ab1deec410b631c0fec0.png)
(3)在线段AB上是否存在点M,使直线PM与
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55a675310c8ba418e5a59beb7317e21e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6b86c22b670a8e9f3896f9e8883fbbb.png)
您最近一年使用:0次
名校
4 . 如图,已知四棱锥
,其中
,
,
,
,侧面
底面
,
是
上一点,且
是等边三角形.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/18/25f65bc1-5e93-47cb-bfc2-9612d39845f4.png?resizew=180)
(1)求证:
平面
;
(2)当点
到
的距离取最大值时,求平面
与平面
的夹角.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.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/3d40978fbe52316daaaa6bdbb403fea0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7ea9d92e5c258a50af1e461c7388894.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b6e6192cf24ada791c26c2d6d434069.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/3d4db9b82b67efe45a02fca32bfcf5dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2b265d121f9ebc13671a5719604476a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/18/25f65bc1-5e93-47cb-bfc2-9612d39845f4.png?resizew=180)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44b190c8d3d7d7d0e6e959e8a52eae90.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc9c9cfa597b444b5c9dbae7a825a695.png)
(2)当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c2bc5e50b8dfa02601c70822252854a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc9c9cfa597b444b5c9dbae7a825a695.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ef796b46e68fe77b117ff0483d2370c.png)
您最近一年使用:0次
2021-02-03更新
|
1754次组卷
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5卷引用:江西省景德镇市2020-2021学年高二上学期期末数学(理)试题
江西省景德镇市2020-2021学年高二上学期期末数学(理)试题(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03 空间向量与立体几何的压轴题(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)湖北省武汉市第三中学2021-2022学年高二上学期10月月考数学试题江苏省盐城市响水中学2021-2022学年高二下学期第一次学情分析考试数学试题
名校
解题方法
5 . 如图,在直三棱柱
中,M为棱
的中点,
,
,
.
平面
;
(2)求证:
平面
;
(3)在棱
上是否存在点N,使得平面
平面
?如果存在,求此时
的值;如果不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3570a95f68349fcd9417fcda62e78e7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bb5b12692517a39c320f99a479eb055.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ef8866ccf160ddc441bf69c5d3a3d5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/547a4b438e2e6687c7cd55ea08bbaae2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de9078475c350c04bd97666d808dd55a.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d1d2e0f281222a5f289ea4008370aed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de9078475c350c04bd97666d808dd55a.png)
(3)在棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f93290b08ab6c1e8f727baa5835fe08.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ac61c24f99a4e466f1e2ea011893866.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8f9fe19dcbe02adcbe8e826c74c7c32.png)
您最近一年使用:0次
2022-06-21更新
|
5191次组卷
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25卷引用:江西省南昌市新建县第一中学2019-2020学年高二开学考试数学(文)试题
江西省南昌市新建县第一中学2019-2020学年高二开学考试数学(文)试题北京西城66中学2017-2018学年高二上学期期中考试数学试题江苏省无锡市江阴市2021-2022学年高二上学期期初摸底检测数学试题辽宁省六校2022-2023学年高二上学期期初考试数学试题北京市第十五中学2017-2018学年高三上学期期中考试数学理试题北京市西城15中2018届高三上学期期中考试数学(理科)试题2019年山西省忻州市静乐县高三下学期6月月考数学试题(已下线)专题8.5 直线、平面垂直的判定及性质 (精讲)-2021年高考数学(理)一轮复习讲练测(已下线)考点24 空间直线、平面的平行、垂直问题-2021年新高考数学一轮复习考点扫描北京市人大附中北京经济技术开发区学校2020-2021学年高一下学期期末测试数学试题江苏省徐州市沛县2021-2022学年高一下学期第二次学情调研数学试题江苏省常州市第二中学2021-2022学年高一下学期5月学情调研数学试题河北省石家庄市十五中2021-2022学年高一下学期6月第三次月考数学试题(已下线)第08练 点线面的位置关系-2022年【暑假分层作业】高一数学(苏教版2019必修第二册)辽宁省鞍山市第三中学2021-2022学年高一下学期期末数学试题(已下线)专题31 直线、平面垂直的判定与性质-2(已下线)8.6.3 平面与平面垂直(精讲)(已下线)专题8.15 空间中线面的位置关系大题专项训练(30道)-2022-2023学年高一数学举一反三系列(人教A版2019必修第二册)安徽省亳州市第二完全中学2022-2023学年高一下学期期末教学质量检测数学试题(A卷)辽宁省大连市第三十六中学2022-2023学年高一下学期6月月考数学试题黑龙江省牡丹江市第一高级中学2022-2023学年高一下学期期中数学试题(已下线)点线面之间的位置关系专题12空间中直线、平面的平行与垂直关系(解答题)(已下线)高一下学期期中复习解答题压轴题十八大题型专练(2)-举一反三系列(人教A版2019必修第二册)(已下线)第八章:立体几何初步(单元测试)--同步精品课堂(人教A版2019必修第二册)
名校
6 . 如图,已知在棱长为1的正方体
中,点
,
,
分别是
,
,
的中点,下列结论中正确的是( )
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/12/22c0d1b0-ae3b-4b1b-906d-a8479d599d50.png?resizew=157)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/212f4416ce8fcd69b531ceda6f6ebfbc.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/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22adbc0da438220f9cace11b629d799b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/12/22c0d1b0-ae3b-4b1b-906d-a8479d599d50.png?resizew=157)
A.![]() ![]() | B.![]() ![]() |
C.直线![]() ![]() | D.直线![]() ![]() |
您最近一年使用:0次
2021-03-22更新
|
487次组卷
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2卷引用:江西省吉安市宁冈中学2023-2024学年高二上学期期末模拟数学试题
名校
7 . 如图所示,在四棱锥
中,底面四边形
是菱形,底面
是边长为2的等边三角形,PB=PD=
,AP=4AF
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/16/a93bb600-1ac6-48dc-b699-8a170222ee71.png?resizew=209)
(1)求证:PO⊥底面ABCD
(2)求直线
与OF所成角的大小.
(3)在线段
上是否存在点
,使得
平面
?如果存在,求
的值;如果不存在,请说明理由.
![](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/1fa0c1a6e9990d435f5df2cba32cc203.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35361e76a7c85d1886728c8d0200b234.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/16/a93bb600-1ac6-48dc-b699-8a170222ee71.png?resizew=209)
(1)求证:PO⊥底面ABCD
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63a253c7fdf589ee3dece13d5b5b5732.png)
(3)在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5865d488a9cf1181016fd2e866177cdd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ae8768996ca9a0f2c5d9a19abbd54df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8180b12d96caf2e6b3ca28a474185e41.png)
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2020-12-05更新
|
2359次组卷
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11卷引用:江西省南昌市豫章中学2021-2022学年高二入学调研(B)数学(理)试题
江西省南昌市豫章中学2021-2022学年高二入学调研(B)数学(理)试题四川省遂宁市安居区2020-2021学年高二上学期期中考试数学(文)试题四川省遂宁市射洪中学2021-2022学年高二上学期第一次月考数学理试题四川省遂宁中学校2021-2022学年高二上学期期中考试数学(文)试题河南省温县第一高级中学2021-2022学年高二上学期12月月考文科数学试题上海市南洋模范中学2022-2023学年高二上学期期中数学试题上海市向明中学2022-2023学年高二上学期10月月考数学试题四川省巴中市恩阳区2022-2023学年高二上学期期中数学试题新疆哈密市第八中学2021-2022学年高二上学期期末数学(理)试题(已下线)期中测试卷01(测试范围:第10-11章)-2023-2024学年高二数学单元速记·巧练(沪教版2020必修第三册)新疆新源县2020-2021学年高一下学期期末联考数学试题
名校
解题方法
8 . 在棱长为
的正方体ABCD—A1B1C1D1中,E是正方形BB1C1C的中心,M为C1D1的中点,过A1M的平面
与直线DE垂直,则平面
截正方体ABCD—A1B1C1D1所得的截面面积为( )
![](https://img.xkw.com/dksih/QBM/2020/6/1/2475398581788672/2476972172959744/STEM/6e3dacd4-6f9a-419d-a8ab-667a3bf73b96.png?resizew=152)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://img.xkw.com/dksih/QBM/2020/6/1/2475398581788672/2476972172959744/STEM/6e3dacd4-6f9a-419d-a8ab-667a3bf73b96.png?resizew=152)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
2020-06-03更新
|
1432次组卷
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8卷引用:江西省景德镇一中2020-2021学年高二上学期期中考试数学(1班)试题
江西省景德镇一中2020-2021学年高二上学期期中考试数学(1班)试题江西省南昌二中2020届高三高考数学(理科)校测试卷题(三)江西省新余市2022届高三上学期期末数学(理)试题江苏省常州市教学联盟2019-2020学年高一下学期期中数学试题(已下线)考点29 空间点、直线、平面之间的位置关系-备战2021年高考数学(文)一轮复习考点一遍过(已下线)考点30 空间点、直线、平面之间的位置关系-备战2021年高考数学(理)一轮复习考点一遍过(已下线)第32练 直线、平面垂直的判定与性质-2021年高考数学(理)一轮复习小题必刷(已下线)专题05 押全国卷(理科)7,9小题 立体几何
9 . 如图,在三棱柱
中,侧面
是菱形,
,
是棱
的中点,
,
在线段
上,且
.
![](https://img.xkw.com/dksih/QBM/2020/3/27/2428136999288832/2428831724412928/STEM/7648d1bf-2ce4-4a60-9b56-6fee5f797583.png)
证明:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fd4c85bb98a2a0afddd7ed92578ad2e.png)
面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a8035fc825a001d7d9a3dacd8271662.png)
若
,面
面
,求
到面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ac4fb99967c46a3855bcf2885b448c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20fc4fbd9390e2a5200920910abc63b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59da0269add3993c134f46169f213907.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86814dbae9a5343d69bb4647900b3bfe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2221fe3118d6d55a78201f1c5296777c.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/5d3bd9abb95b0e96333873fc454e03a7.png)
![](https://img.xkw.com/dksih/QBM/2020/3/27/2428136999288832/2428831724412928/STEM/7648d1bf-2ce4-4a60-9b56-6fee5f797583.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9bf6c84731e5e1bd335ecfc2d36c3d81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fd4c85bb98a2a0afddd7ed92578ad2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895d6f710d5f67e1d4c7408d50d77281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a8035fc825a001d7d9a3dacd8271662.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f53190d6ead827a6338b9de847aeaf1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45224f7eac9d0cef64bf28d93e7721a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2013579652aa5f53d43080856f01c374.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20fc4fbd9390e2a5200920910abc63b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/445cfd832967db6bbaa0a2ea311b4f0d.png)
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2020-03-27更新
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993次组卷
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2卷引用:江西省吉安市第一中学2021-2022学年高二10月第一次段考数学(理)试题
解题方法
10 . 如图,在四棱锥
中,
,
,
,且
,
.
![](https://img.xkw.com/dksih/QBM/2020/3/18/2422133807710208/2422983057113088/STEM/34494107f04d439aa5267764898d604d.png?resizew=200)
(1)证明:
面
;
(2)在
上是否存在点
,使
平面
,若存在,请计算
的值,若不存在,请说明理由;
(3)若
,求点
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bafa8c14100a4f847b41b9148954116c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34e0a957a55460c72673c0f2ee90dbb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdb2dd10731b99c0f4f89ee957f8a239.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0277ebb355020d31b59861842ca379ae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b80ee363635d73f601654339028daec.png)
![](https://img.xkw.com/dksih/QBM/2020/3/18/2422133807710208/2422983057113088/STEM/34494107f04d439aa5267764898d604d.png?resizew=200)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)在
![](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/30067b7b236d17af8a462f96a58d11bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb304d905125170bebfada27e7ed8960.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced22fbe85d4a749c7b0b6bbae3ea3e7.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8676b624f105072a3185911b25c912dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb304d905125170bebfada27e7ed8960.png)
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