如图1,在正方形
中,点
分别是
的中点,
与
交于点
为
中点,点
在线段
上,且
,现将
分别沿
折起,使点
重合于点
(该点记为
),如图2所示.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/7/10e26756-b91c-4794-acae-ec4fc65c9e2f.png?resizew=270)
(1)若
,求证:
平面
;
(2)是否存在正实数
,使得直线
与平面
所成角的正弦值为
?若存在,求出
的值;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/374fe9986ebbc986fc422e514ab93a51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df4b833fb7dd03c34ac40c664cd8483d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4aa0df7f1e45f9de29e802c7f19a4f64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bcdae78f4d3b8d8213ac3ac9a9567eb5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abfa5f1a07c56cabb83b5652844ecd5e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15fb65174c514af953f0a464f052d466.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0e1b35ce4e9edff774c986d78e4b39f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/098a3e7d1f1890863b7483a98b618119.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/7/10e26756-b91c-4794-acae-ec4fc65c9e2f.png?resizew=270)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f2f2d7c81cb44416bcdf59419637682.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4cbcd5cd33ce6cb040b353599893aa6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d246f9eceab371ebf47a47c2f11a4ad.png)
(2)是否存在正实数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7032213f46269954ee14876934031909.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/041bac006360df1095a51b078765ef6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
更新时间:2017-02-08 11:36:53
|
相似题推荐
解答题-证明题
|
适中
(0.65)
解题方法
【推荐1】如图,在直四棱柱
中,底面
是边长为2的菱形,且
,
.
![](https://img.xkw.com/dksih/QBM/2020/7/22/2511299987103744/2513042037645312/STEM/149c3e3ab2d44d17b68305a1f64f772e.png?resizew=222)
(1)求证:
;
(2)求二面角
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/f945a69cf7e8213e50622125cde652f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/094d33b3391c631946ca24a03fb2eb0a.png)
![](https://img.xkw.com/dksih/QBM/2020/7/22/2511299987103744/2513042037645312/STEM/149c3e3ab2d44d17b68305a1f64f772e.png?resizew=222)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85d0f0cd1f94cea4aec68e4d830bed54.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3454001fb80a2018c76aaf5b5219c8b9.png)
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【推荐2】如图,四棱锥P-ABCD中,AB⊥AC,AB⊥PA,AB∥CD,E,F,G,M,N分别为PB,AB,BC,PD,PC的中点.求证:平面EFG⊥平面EMN.
![](https://img.xkw.com/dksih/QBM/2016/12/21/1826264499724288/1826264500264960/STEM/ae57c45ed51b45f092243a1ef339fe34.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
解题方法
【推荐1】如图,在四棱锥
中,底面
为平行四边形,
平面
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/31/3dcda66c-ebd0-4416-9120-3aeb797c3c05.png?resizew=160)
(1)建立空间坐标系,写出平面
的一个法向量的坐标;
(2)若
与平面
所成角为
,求二面角
的大小.
![](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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c4cb73e9d976cbfe9c590044fa69dd5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/650c6c818df102a83ce5159e3208d01a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21ea52361458ce2e49ed0fe99d8e6c02.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/31/3dcda66c-ebd0-4416-9120-3aeb797c3c05.png?resizew=160)
(1)建立空间坐标系,写出平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83c7a937699f989b685f285041434000.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79a97bb4dcfab4ec7539bc783d563c49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1069d514c3c32aeabd274475ee209ed6.png)
您最近一年使用:0次
解答题-证明题
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适中
(0.65)
名校
【推荐2】已知在三棱锥
中,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
面
,
,且
,点
是
的中点,作
交
于点
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/24/e2a8287f-601e-4208-98f3-31238110c863.png?resizew=143)
(1)求证:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
平面
;
(2)求二面角
的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1633988fd62a652de726ee92a917b52d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/615fc8790237a1b09af51d6bcad6b595.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4364556ea734587d846c54948432b8d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a4a6a1e70241d600bc6c104313eac61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/24/e2a8287f-601e-4208-98f3-31238110c863.png?resizew=143)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1633988fd62a652de726ee92a917b52d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b03428a8f91a5674cb8f54766c165f7e.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b33b7213d99a817bff19bcf740a0697c.png)
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解答题-证明题
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(0.65)
名校
解题方法
【推荐1】如图,在多面体
中,面
为正方形,面
和面
为全等的矩形,且均与面
垂直.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/4/f85cf423-c985-4876-90f0-cdaf3c5d17d7.png?resizew=174)
(1)求证:平面
平面
;
(2)若直线
和平面
所成角的正弦值为
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d20e38a1b5cfffd43a3405481a1d67cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/369eb8ad56da7dc1cdb7c43762be4bee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50cfd99a702ee24f9ef94e4b6f50101f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/4/f85cf423-c985-4876-90f0-cdaf3c5d17d7.png?resizew=174)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dff29779a860ddd0f6fcc74f29678e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09219dbd440c70d66bf2bf8b4c2bfe2f.png)
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dac452fbb5ef6dd653e7fbbef639484.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb825a9777a4d0aa62b8d764e4ad0d26.png)
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解答题-问答题
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适中
(0.65)
解题方法
【推荐2】如图,四棱锥
的底面
是矩形,
底面
,点
分别在
上, 且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/9/72c31fb0-85a9-48ec-a152-67dac6ebd895.png?resizew=178)
(1)证明:
平面
;
(2)若直线
与平面
所成角的正弦值为
,求
.
![](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/c45fbffb9e2c7fa7c5006cde8da0cabe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21009ca3f075e52d5ead1a1c1607b387.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00430f53b989f7137333e10e27b61047.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8114bce49be13ddd7bcf685a5239f650.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/9/72c31fb0-85a9-48ec-a152-67dac6ebd895.png?resizew=178)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06222ee533c2484ab25321a6abbf98cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a4d781525777c7b5284dffc70b2a28a.png)
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fa3254460ecbacecb3e57c5dce227f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f429614954d7a6d1e5f6df901b4d5d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdba1337ec85fa9722cb4b320a82ae6.png)
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【推荐3】如图所示,在直四棱柱
中,
为
上靠近点
的三等分点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/12/a4cda8e4-7537-4a08-b5ac-d7ee248b3a91.png?resizew=143)
(1)若
为
的中点,试在
上找一点
,使
平面
;
(2)若四边形
是正方形,且
与平面
所成角的正弦值为
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/12/a4cda8e4-7537-4a08-b5ac-d7ee248b3a91.png?resizew=143)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ee72dbf16db9bb8b5b51576a0619c06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e4755dc59cb5a03cd39879bc80fdbb9.png)
(2)若四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e4755dc59cb5a03cd39879bc80fdbb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a2008b78a906cf5ecdfd68432fa9ad1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2facd6d61019612fec94df8b6e178e5.png)
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