已知平面
平面CDEF,四边形CDEF为矩形,
,
,M,N分别为BD,CF的中点,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/5/000be1ee-57bd-41fe-b199-643d89ccf426.png?resizew=201)
(1)证明:
平面BEF;
(2)求直线MN与平面ABE所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cf9a6db3571fa57bfa2d5e4d44c51b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6dceb5cc71fc50f20649f6b9535fd914.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080db3af81b29ed10144a1c2e2a4fb8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b746fe4bc5e1a1e998dcecde1911007.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/efc6e4b936d7a800e839a30c3839574d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/5/000be1ee-57bd-41fe-b199-643d89ccf426.png?resizew=201)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edcf19a7f0dd0cdf59516ae585025110.png)
(2)求直线MN与平面ABE所成角的正弦值.
更新时间:2022-05-04 11:11:37
|
相似题推荐
解答题-证明题
|
适中
(0.64)
【推荐1】如图,在四棱锥
中,底面
是正方形,
,
分别为
中点,
.
![](https://img.xkw.com/dksih/QBM/2016/4/7/1572568586182656/1572568592039936/STEM/d2a62a0f6bab468a9088cbc5af8948a3.png)
(I)求证:
;
(II)求二面角
的余弦值;
(III)在棱
上是否存在一点
,使
?若存在,指出点
的位置;若不存在,说明理由.
![](https://img.xkw.com/dksih/QBM/2016/4/7/1572568586182656/1572568592039936/STEM/89e1ab8c348c44cba89d338b7c2da510.png)
![](https://img.xkw.com/dksih/QBM/2016/4/7/1572568586182656/1572568592039936/STEM/79a280db790f4c43931a54e3fa03c2af.png)
![](https://img.xkw.com/dksih/QBM/2016/4/7/1572568586182656/1572568592039936/STEM/9be540cc8ad64fa58d0eac084b02f297.png)
![](https://img.xkw.com/dksih/QBM/2016/4/7/1572568586182656/1572568592039936/STEM/365ab779cd864647846a6a63c5755bf1.png)
![](https://img.xkw.com/dksih/QBM/2016/4/7/1572568586182656/1572568592039936/STEM/1be82fdcf4d542c39f334e3d4d4ef9ff.png)
![](https://img.xkw.com/dksih/QBM/2016/4/7/1572568586182656/1572568592039936/STEM/e0b7662530994c318acdaf0b60e1595b.png)
![](https://img.xkw.com/dksih/QBM/2016/4/7/1572568586182656/1572568592039936/STEM/d2a62a0f6bab468a9088cbc5af8948a3.png)
(I)求证:
![](https://img.xkw.com/dksih/QBM/2016/4/7/1572568586182656/1572568592039936/STEM/81b47f4c4d304e1ea923767fb9865343.png)
(II)求二面角
![](https://img.xkw.com/dksih/QBM/2016/4/7/1572568586182656/1572568592039936/STEM/a93fd55091a84f4289da0ccb1b81c3e1.png)
(III)在棱
![](https://img.xkw.com/dksih/QBM/2016/4/7/1572568586182656/1572568592039936/STEM/ac49e8a5b3a246c287e962b59b292d6e.png)
![](https://img.xkw.com/dksih/QBM/2016/4/7/1572568586182656/1572568592039936/STEM/fef732636c694834988a7fe9f695e43f.png)
![](https://img.xkw.com/dksih/QBM/2016/4/7/1572568586182656/1572568592039936/STEM/2639f6a171034a48aebf7205d0abf138.png)
![](https://img.xkw.com/dksih/QBM/2016/4/7/1572568586182656/1572568592039936/STEM/fef732636c694834988a7fe9f695e43f.png)
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解答题-证明题
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解题方法
【推荐2】如图1,已知三棱锥
,图2是其平面展开图,四边形
为正方形,
和
均为正三角形,
,
分别为
,
的中点,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/2/650f264e-f75f-4f05-9ad1-f72e6e827293.png?resizew=488)
(1)求证:
;
(2)求二面角
的余弦值;
(3)若点
在棱
上,满足
,
,点
在棱
上,且
,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e742966e3711cfa53dce04022acf4bcc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6830ebecddbd9759be626289c408e4f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68b40d0d2f3cdd8981bb792ad87efb42.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/2/650f264e-f75f-4f05-9ad1-f72e6e827293.png?resizew=488)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7c545dcccb34fd8f83bfb23f2d1c23b.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74ec3d90e5f12cd8946d4dc638c1a357.png)
(3)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40f095541d8ac2d972743d3200f22e30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f297d79758d8803193db804f99b8909.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdba1337ec85fa9722cb4b320a82ae6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79498e1df1280868532f59ee8059a223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07b1e52dfd144ab4afda4d4aa5a92c1f.png)
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真题
解题方法
【推荐3】已知空间四边形
中
,M,N,P,Q分别是边
的中点(如图).求证:
是一个矩形.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f0f6ef719c80878318cd86e95ef8cb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a337a934b801730321f67b0e5a0b144f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/389bc3f29c058067e06e0d0d2be399da.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/11/d4cba854-c4ea-4f7a-bf78-9d9f248d3b05.png?resizew=135)
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解答题-证明题
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适中
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名校
【推荐1】棱锥
中,底面
是矩形,
底面
,
是
的中点,已知
,
,
,求:
![](https://img.xkw.com/dksih/QBM/2020/10/15/2571494194323456/2571859572441088/STEM/a02f0bb3374f47a3a0cd0eb94b77a3a0.png?resizew=187)
(1)求证:PA//平面BED;
(2)求异面直线
与
所成的角的大小.
![](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/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.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/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9c3ec174b1ce835cc8737ff6ce57e52.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b80ee363635d73f601654339028daec.png)
![](https://img.xkw.com/dksih/QBM/2020/10/15/2571494194323456/2571859572441088/STEM/a02f0bb3374f47a3a0cd0eb94b77a3a0.png?resizew=187)
(1)求证:PA//平面BED;
(2)求异面直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
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【推荐2】如图,在等腰直角
中,
,
和
都垂直于平面
,且
,
为线段
上一点,设
(
).
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/27/2626150b-8605-47de-b823-0370d2c59213.png?resizew=124)
(1)当
为何值时,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
平面
;
(2)当二面角
的余弦值为
时,求四棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06154cae3bf7a8ce5a1e97a7380875.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d97dc3b752832906de41447bb58a341.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fc56c77464a17a1e97b568762a3e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43871d8531150e25bd32a4e907ebc920.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/400d40ea1ce4dece1bbc6d0d1802972c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/540ccd15435aa2d59e809d6a28fb2467.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/27/2626150b-8605-47de-b823-0370d2c59213.png?resizew=124)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)当二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7736708fac981f6e321f8b244c8c8317.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/743c08870d66a766fa25298adf4dbf89.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8bfb63b3c8acac52602669807b91c111.png)
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适中
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【推荐3】如图,已知四棱锥
中,
,BC=DC=2AB=4,CB⊥CD,
,点Q在棱PA上,PQ=2QA,且PA⊥平面QBD.
(1)求证:
平面QBD;
(2)求PC与平面PAB所成角的正弦值.
![](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/4c85aeab3aeaf4367b711da8cde2e8bd.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/10/40eb36a2-ed4f-4da8-8c3a-0f0ea6cac41a.png?resizew=141)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6bb178784aa857d4d4683e650273f054.png)
(2)求PC与平面PAB所成角的正弦值.
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名校
【推荐1】如图,直三棱柱
中,
,
为
的中点,
为棱
上一点,
.
![](https://img.xkw.com/dksih/QBM/2022/3/9/2932583987544064/2933819910561792/STEM/cf3c8f0d-3c95-4889-8689-c2e188551da6.png?resizew=165)
(1)求证:
平面
;
(2)若二面角
的大小为
,求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e96a6b20a35af7755e5d90789ea862da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.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/f9499f0e312799d87f5377f30565abc6.png)
![](https://img.xkw.com/dksih/QBM/2022/3/9/2932583987544064/2933819910561792/STEM/cf3c8f0d-3c95-4889-8689-c2e188551da6.png?resizew=165)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ffc6952e988d04f22f0fb2f7f0ab7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfb3f0b5d8bf98eeff66f43b7dcbb4be.png)
(2)若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e0dbea030ddff17bc48a6d976395c5d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ac09dc1ca2cdd7aef28c218763d3e4d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb5a463a03c549b0dba6d90e7f16a2af.png)
您最近一年使用:0次
解答题-证明题
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适中
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【推荐2】如图所示,已知三棱台
中,平面
平面
,
是正三角形,侧面
是等腰梯形,
,
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/2/c950649d-3360-41db-9e95-0a58ef2173ce.png?resizew=213)
(1)求证:
;
(2)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eff0db05826cbff651faf0144904b32.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/923cadcb4df5a9bcec2805f4d250786f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/2/c950649d-3360-41db-9e95-0a58ef2173ce.png?resizew=213)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc0a886f1192d450ced9fd875e78425e.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13cf3a313649d7b92f28dd9fb8c27e41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
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【推荐3】如图①,
,将图①中左右两个三角形沿着
翻折成为图②所示的三棱锥,棱
上的点
满足
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/18/d762f87b-936e-4b11-95e2-a5828ad05ba9.png?resizew=373)
(1)过点
作截面
平面
,写出作法并证明;
(2)当二面角
的大小为
时,求直线
与(1)中平面
所成角的正切值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51a584d06388fd4fd142832bc2205639.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/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7420dde38d656e3926e8228d81c13277.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/18/d762f87b-936e-4b11-95e2-a5828ad05ba9.png?resizew=373)
(1)过点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/414844edd458857bdfc80bffa61cbf9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
(2)当二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ec2524be492bca0d1566bf848066f10.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/231b861d6d1f1d0b9f52b041cb40eb62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
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