在四棱锥
中,四边形
为菱形,
,且平面
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/13/e2696cb4-43c9-4b37-bd2d-3452d6144384.png?resizew=157)
(1)证明:
平面
;
(2)若
为
上一点,且
,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/d9d213b9dda73534315f22e88870dacf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d077f6da8b2c00b152d4679aa2ed7f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/13/e2696cb4-43c9-4b37-bd2d-3452d6144384.png?resizew=157)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)若
![](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/789c9c79846abc6ba99cf3e575cdae6f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e55acf08a1fe8bea7a4822d8718dbc09.png)
更新时间:2022-03-17 17:05:54
|
相似题推荐
解答题-证明题
|
适中
(0.65)
解题方法
【推荐1】如图,在直三棱柱
中,
与
相交于点
,
为
的中点,
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/26/42ad4db5-6a46-481b-88ea-53e6275f6d86.png?resizew=150)
(1)求证:
平面
;
(2)若
,
,求证:
平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b470c4e195cf7a07b7a331ce4b436e03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e26d9636ad77369535852c6e4493446a.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/56f7ba05c54b3de1f4378f7c8eb58328.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/26/42ad4db5-6a46-481b-88ea-53e6275f6d86.png?resizew=150)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7592c4f01c8e06c7ee90df5b9413a9f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ac61c24f99a4e466f1e2ea011893866.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/615fc8790237a1b09af51d6bcad6b595.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/686849a983d24dd62270b2967708cc24.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93cf663ee2bf1ac5c43f4306fa0cf250.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9afac7c616bbb14e1ed428a3c507c7dc.png)
您最近一年使用:0次
解答题-问答题
|
适中
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名校
【推荐2】如图,四边形
为菱形,
,将
沿
折起,得到三棱锥
,点M,N分别为
和
的重心.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/15/532c4dbc-6d2b-450b-a7b4-3af6a6222db2.png?resizew=296)
(1)证明:
∥平面
;
(2)当三棱锥
的体积最大时,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f9b0e2a09c7cddb40cea36cbade9b0d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ac451db3443cabb204f96c31fd4a02e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4357d5744046d4d44abb09e1ee35fcb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab2a2834d80ff574e79eae8ca8d4e94f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/15/532c4dbc-6d2b-450b-a7b4-3af6a6222db2.png?resizew=296)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/212a67f115d1cbe69f100b489babe5f8.png)
(2)当三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4357d5744046d4d44abb09e1ee35fcb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6230ec526fcab9f2e73901cca0a5a5f0.png)
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【推荐3】如图甲,三棱锥
,
均为底面边长为
、侧棱长为
的正棱锥,且四边形
是边长为
的菱形(点
在平面
的同侧),
交于点
.
![](https://img.xkw.com/dksih/QBM/2020/12/18/2616689889361920/2617731238821888/STEM/0ecaf12b-fe22-4894-bf9e-ebd58cffbd9b.png?resizew=320)
![](https://img.xkw.com/dksih/QBM/2020/12/18/2616689889361920/2617731238821888/STEM/d57baafc-50d1-4906-a56b-d9228f827e34.png?resizew=318)
(1)证明:平面
⊥平面
;
(2)如图乙,设
的延长线交于点
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ddfe0ccf24d760c77535a70c92dad145.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a4ccef06bd7c89746239123517347c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38387ba1cadfd3dfc4dea4ca9f613cea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f83dbfddc6f98548699ed581e8c8608.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38387ba1cadfd3dfc4dea4ca9f613cea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6bce3d91ca23b86d8c6625f2632e437.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73b3c032441543354c154ee67d744abb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://img.xkw.com/dksih/QBM/2020/12/18/2616689889361920/2617731238821888/STEM/0ecaf12b-fe22-4894-bf9e-ebd58cffbd9b.png?resizew=320)
![](https://img.xkw.com/dksih/QBM/2020/12/18/2616689889361920/2617731238821888/STEM/d57baafc-50d1-4906-a56b-d9228f827e34.png?resizew=318)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdc98077dbfeb14fc98602fdbfda4121.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)如图乙,设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64f11727b586baf07b63c77be70a4d73.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f45c7733405e33ab597a2116ae363cf.png)
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解答题-证明题
|
适中
(0.65)
【推荐1】如图,
是以
为直径的半圆
上一点,
垂直于圆
所在的平面.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/19/a9bbb05f-75a8-479c-b529-7bed64ed89b7.png?resizew=160)
(1)求证:
平面
;
(2)若
,
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/19/a9bbb05f-75a8-479c-b529-7bed64ed89b7.png?resizew=160)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca5dd496ee0c1170ef6dcc48266ee444.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dbb78cdb972880c4a69ef564f2ccfcbd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d20b57ab134b3d3dbe9b1d35ad762384.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca6d1c5eace748465b2dad5065f5111c.png)
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(0.65)
名校
【推荐2】如图,正方体
,棱长为
分别为
上的点,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/19/5019cc1c-2e46-4514-8d69-333d198349cd.png?resizew=216)
(1)当
时,求异面直线
与
所成的角的大小;
(2)当
为何值时,三棱锥
的体积最大?
(3)求三棱锥
的体积最大时,二面角
的正切值;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8facdca5180b1b029fbe71f549f557e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94e731b605eba332df44bea683c4aee5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/582fca0c1348fbbf733909680affa238.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/19/5019cc1c-2e46-4514-8d69-333d198349cd.png?resizew=216)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54b53b86bd516400d6fa7dabb3603f31.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ce1b066f8869d0ff4513f7a99745125.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3fc725182c2fd1413319fea35b95c7dc.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ade5f5065c542ceddf3df5cd3e688d7.png)
(3)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ade5f5065c542ceddf3df5cd3e688d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69e2871593862c9b4726d913873b2091.png)
您最近一年使用:0次
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适中
(0.65)
【推荐3】如图,三棱锥
中,
,
,平面
底面
,
、
分别是
、
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/21/0ae74152-e8fc-4e17-b874-0aa0c23f39bd.png?resizew=155)
(1)证明:
平面
;
(2)求二面角
的正切值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf2db8e379fbb1ade525d25e60f35fb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac34466d49ce1fe5dd29d02f02e5cd5b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78a3fd5284e160896f07ce367645fd04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/21/0ae74152-e8fc-4e17-b874-0aa0c23f39bd.png?resizew=155)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55e766cfdbb0812c4add7596f7bf87e4.png)
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名校
【推荐1】如图,四棱锥
中,面
面
,
是以
为斜边的等腰直角三角形,
,
,
,
为
的中点.
![](https://img.xkw.com/dksih/QBM/2020/7/13/2505228609298432/2506554643038208/STEM/a6b0270e-d62d-4e96-987f-4465ea1d8205.png)
(1)求证:
;
(2)求直线
和平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55a675310c8ba418e5a59beb7317e21e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f79863ffcfa63117ca6741b20a48e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080db3af81b29ed10144a1c2e2a4fb8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20e4a7519a73268f7d6438d0ba6969eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/2020/7/13/2505228609298432/2506554643038208/STEM/a6b0270e-d62d-4e96-987f-4465ea1d8205.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e37c9f2fec8e6966125547af2628d9bf.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc5adb5eb60ae4435a12d93854066298.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f571a1aac46c6d0cf440c0ec2846bf9.png)
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解答题-证明题
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适中
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【推荐2】如图,在三棱锥
中,平面
平面
,
,
,
,
分别为线段
上的点,且
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/13/b820a9e9-4f84-4392-99f6-993ad32425b5.png?resizew=195)
(1)求证:
平面
;
(2)若
与平面
所成的角为
,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/305a88d4e0249bd16d48eda01331d2d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ffc2817fa590affb5a760a25dc65308.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9538281f10aa8129a3d0cc49a0370db5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91e1e4115d78e625e9e0f47cdade3286.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/374fe9986ebbc986fc422e514ab93a51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50196d293a863fe2f9e46199052ab8c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4148817c0a463417ec02769a7abc5913.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2951b9f77413d5f062acb300b09de1f6.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/13/b820a9e9-4f84-4392-99f6-993ad32425b5.png?resizew=195)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97f30533da2e1d2a958dc906c37eba9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af9955b5aebb73cd84447e8541f901ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
您最近一年使用:0次