如图,已知四棱锥
底面
为菱形,
平面
,
,
分别是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/20/948d2d62-f888-44b4-858b-5c260650b9be.png?resizew=171)
(Ⅰ)证明:
;
(Ⅱ)若
为
上的动点,
,
与平面
所成最大角的正切值为
,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/362a28fb4dc71e5c5c747476089b1f37.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/05740f0c6071846227dc0ec177ad15e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1683fed718259fa7b77ced8be46c87.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/20/948d2d62-f888-44b4-858b-5c260650b9be.png?resizew=171)
(Ⅰ)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/304e9d63e7fdc531f4f7b805b765a1b1.png)
(Ⅱ)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/589786dd7c3a2679c3230b671cd232d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/839c7616cd0d90265f4b2c9c021254fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9072b69d2f0d27f940a49f1db4b27fcc.png)
更新时间:2020-09-04 15:03:54
|
相似题推荐
解答题-问答题
|
适中
(0.65)
名校
【推荐1】如图,四棱锥
中,
底面
,
,
,
,
,E为棱
上的点,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/18/3f4ce94b-6278-4c94-940b-739e1bca8d33.png?resizew=170)
(1)证明:平面
平面
;
(2)求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fb2e071d4e01107dcf7d95cbb86b415.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/4a0e5697eca3f5205cb7b343648240bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d262480ffb55b7617f44b63f130c154a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99d24703c6de41c2df507d5405f377ad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d4db9b82b67efe45a02fca32bfcf5dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a82a8bc0e66fd0bd01a8f0c807be31a5.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/18/3f4ce94b-6278-4c94-940b-739e1bca8d33.png?resizew=170)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3cc2b3a37ddb402589bd04351247a1d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21665d21bbfb04410c78345de1fd15ae.png)
(2)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d244fd5f3333d94280e70f31c4b50723.png)
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【推荐2】如图,正方形
与正方形
所在平面互相垂直,
、
分别在
,
上,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/19/5b24e114-5eb7-48fd-9db5-f542adabfe1f.png?resizew=178)
(1)证明:
;
(2)证明:
平面
;
(3)求平面
截三棱柱
所成大小两部分的体积比.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7df2aeef0359590344c309f800a6f76d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07cbd64af2cc21a9b8ed58f38e139e0d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/19/5b24e114-5eb7-48fd-9db5-f542adabfe1f.png?resizew=178)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dee50a23604ea2a9c1f3649dab97c2e7.png)
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94270844f197d524bf1da4f1385befd2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/212a67f115d1cbe69f100b489babe5f8.png)
(3)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/212a67f115d1cbe69f100b489babe5f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e5089d811caeed93dc3bcc108d122a2.png)
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【推荐1】如图,已知三棱锥PABC,∠ACB=90°,D为AB的中点,且
是正三角形,PA⊥PC.求证:
![](https://img.xkw.com/dksih/QBM/2022/2/4/2909035249508352/2956308421738496/STEM/c539db489bbc49e1964039f41804df75.png?resizew=162)
(1)PA⊥平面PBC;
(2)平面PAC⊥平面ABC.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0bb4ef08f6070a6bbc54ea9c4f130d5.png)
![](https://img.xkw.com/dksih/QBM/2022/2/4/2909035249508352/2956308421738496/STEM/c539db489bbc49e1964039f41804df75.png?resizew=162)
(1)PA⊥平面PBC;
(2)平面PAC⊥平面ABC.
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【推荐2】如图,
是以BC为底边的等腰三角形,DA,EB都垂直于平面ABC,且线段DA的长度大于线段EB的长度,M是BC的中点,N是ED的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/55515982-d022-40f5-9f5a-fa0b79220a0e.png?resizew=150)
求证:(1)
平面EBC;
(2)
平面DAC.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/55515982-d022-40f5-9f5a-fa0b79220a0e.png?resizew=150)
求证:(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d0edb1508fc95765f3bb316bcb5252d.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7592c4f01c8e06c7ee90df5b9413a9f5.png)
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【推荐3】如图所示,已知三棱柱
中,
,
,
.
![](https://img.xkw.com/dksih/QBM/2017/3/6/1637839852494848/1637863346249728/STEM/1cad55e92aad48e89b7c0c29ab6c6ab9.png?resizew=137)
(1)求证:
;
(2)若
,
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33de9b94a20b9d6ea37cfe135d790801.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd3464f6bd34d82906cf47ad4032d08f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6cf66d6e9ae6fa35f22233cd75ca2501.png)
![](https://img.xkw.com/dksih/QBM/2017/3/6/1637839852494848/1637863346249728/STEM/1cad55e92aad48e89b7c0c29ab6c6ab9.png?resizew=137)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7870cee007535b979d35bc7feab75616.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da124d4a07030677f9937554eee8ee95.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5786400af61b187f938f26a9f71b45be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2e718d2042232538370f5168f7eb9a1.png)
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解题方法
【推荐1】如图,在三棱锥A-BCD中,AB⊥平面BCD,E为棱AC上的一点,且BE⊥平面ACD.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/14/9ad79e88-a1b6-4cef-bfa6-69edda63be6b.png?resizew=136)
(1)证明:BC⊥CD;
(2)设BC=CD=1,BC与平面ACD所成的角为45°,求二面角B-AD-C的大小.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/14/9ad79e88-a1b6-4cef-bfa6-69edda63be6b.png?resizew=136)
(1)证明:BC⊥CD;
(2)设BC=CD=1,BC与平面ACD所成的角为45°,求二面角B-AD-C的大小.
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【推荐2】已知四面体
,
,且平面
平面
.
![](https://img.xkw.com/dksih/QBM/2015/7/9/1572173719412736/1572173725474816/STEM/a1994ec89e5e43c79b78ba5c28e2aa8e.png?resizew=199)
(Ⅰ)若
,求证:
;
(Ⅱ)求二面角
的正切值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2197c948c619169ef80441678c0b508.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcf6dc837ae85207789b94d109c5c2eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://img.xkw.com/dksih/QBM/2015/7/9/1572173719412736/1572173725474816/STEM/a1994ec89e5e43c79b78ba5c28e2aa8e.png?resizew=199)
(Ⅰ)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd95dc30c0344788b94289c464a3158e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70734a8e672376bb0bd1522e229f86a2.png)
(Ⅱ)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81ca12f11f39405a6a49042c5e294862.png)
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【推荐1】如图,直三棱柱
的底面是边长为2的正三角形,
,
分别是
,
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/13/fb36c4f7-69c7-47db-80e2-9e2a51664ab7.png?resizew=188)
(1)证明:
平面
;
(2)若直线
与平面
所成的角为
,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.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/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/13/fb36c4f7-69c7-47db-80e2-9e2a51664ab7.png?resizew=188)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f4c3f9dd5d0343597a7f58a1989b537.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f96c673a2381f118ea2d3efc0bca1f3.png)
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ee8456443402a25b1e25d35ff7e1c98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9b7b7793d29d66dfdd89e7a6564a35c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79a97bb4dcfab4ec7539bc783d563c49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/062e008fb2224a797b360a10e0c4e688.png)
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【推荐2】如图,直三棱柱
的底面是边长为4的正三角形,
,
分别是
,
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/1/19d40e44-310d-4439-8ea6-e69bdd4e034e.png?resizew=178)
(1)证明:平面
平面
;
(2)若直线
与平面
所成的角为
,试求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.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/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/1/19d40e44-310d-4439-8ea6-e69bdd4e034e.png?resizew=178)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72c9831963e3d8ca278fbf96908b0075.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f96c673a2381f118ea2d3efc0bca1f3.png)
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ee8456443402a25b1e25d35ff7e1c98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9b7b7793d29d66dfdd89e7a6564a35c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6b86c22b670a8e9f3896f9e8883fbbb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2149d89a480dc0c1e24ef775ca881cb3.png)
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【推荐3】如图,
是圆锥的顶点,
是圆锥底面的圆心,其轴截面是正三角形,点
是
上一点,
,点
、
是底面圆
上不同的两点,
是
的中点,直线
与圆锥底面所成角
满足
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/10/8b163544-f216-41d1-b089-88fabdec2221.png?resizew=159)
(1)求证:
;
(2)求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b68df477b3ee45ac0f725db00d465a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18e5ef91fb27dd684a27ae7f1993cfba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50be166fa22ab8e40105b6eb8ba3d347.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a6e2867f32d3f1c3cd36cd3a11a8580.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24c8f7a92218d445f2aaa88e5e44cd59.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/10/8b163544-f216-41d1-b089-88fabdec2221.png?resizew=159)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf6ac4c25ab4a00a611013d45bfc1ea1.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ba6a22627cd33a03a95c2c964747624.png)
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