如图,在直四棱柱
中,底面四边形
是边长为2的正方形,
,点
,
分别为棱
,
的中点.
(1)证明:
平面
;
(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/e55a2310cbba5e050488cd9296eb195d.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/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/18/6c18db86-63c7-46e8-9c21-9965f98c2527.png?resizew=129)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f3fcc14ec67dc9a10bee27b3b700ea2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f6b1a6adac644c48cab9ec4d392a152.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ecec1c6a7ac4632c13976db358bcb05e.png)
更新时间:2024-02-18 18:49:39
|
相似题推荐
【推荐1】如图,四棱台
中,上、下底面均是正方形,且侧面是全等的等腰梯形,
,
分别为
的中点,上下底面中心的连线
垂直于上下底面,且
与侧棱所在直线所成的角为
.
(1)求证:
∥平面
;
(2)求点
到平面
的距离;
(3)边
上是否存在点
,使得直线
与平面
所成的角的正弦值为
,若存在,求出线段
的长;若不存在,请说明理由
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d134433600df75f2a5d0f35deb2cac90.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ced9844fe2e052c70486af0740afa63.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae0a4f38420bb9215dbc9c875b755838.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae0a4f38420bb9215dbc9c875b755838.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1e5fa72f2878b476bc57f0df12d6555.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/27/0057a024-50ff-4829-ba70-d50596cf58d9.png?resizew=188)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fe734023d4e70010a6b2cc3267cb86e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bff3ccea5989c60e51e321af3f53f54.png)
(2)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bff3ccea5989c60e51e321af3f53f54.png)
(3)边
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9399c9a2a31b0e3165aea2d6ccc4f7c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bff3ccea5989c60e51e321af3f53f54.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d9662368fd788afb77b79035cdd268b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69d2b798744645af88a4fa411344a83.png)
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【推荐2】如图,已知三棱柱
中,侧棱与底面垂直,且
,
,
、
分别是
、
的中点,点
在线段
上,且
.
![](https://img.xkw.com/dksih/QBM/2021/5/2/2712391979089920/2714010239172608/STEM/2733a15f-477f-4d2f-8714-5f9d6f0dfdca.png?resizew=244)
(1)求证:不论
取何值,总有
;
(2)当
时,求平面
与平面
所成锐二面角的余弦值;
(3)当直线
与平面
所成角的正弦值为
时,求实数
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/002c709e9fee8d477bddfe595cc760f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36c4559d27e3905980d1a4f1856f07de.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/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f7baf1a8607125e0e5220b5baf03263.png)
![](https://img.xkw.com/dksih/QBM/2021/5/2/2712391979089920/2714010239172608/STEM/2733a15f-477f-4d2f-8714-5f9d6f0dfdca.png?resizew=244)
(1)求证:不论
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e4ece75fe9b8555909be5a00d2b7af0.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73b3cf0f585938ede9eca890a6eb326d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22ce50ba5e349425274f05d46d120a74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(3)当直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d50703c46b6153945d718b198f03b4b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22ce50ba5e349425274f05d46d120a74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38cb57b942813635ef4e4c3bea67928f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
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解答题-问答题
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适中
(0.65)
【推荐1】如图已知
是边长为
的正方形
的中心,点
分别是
的中点,沿对角线
把正方形
折成二面角
.
![](https://img.xkw.com/dksih/QBM/2017/4/21/1670758700146688/1672110284587008/STEM/b5aa502578c343d6a661ecd6b1878b14.png?resizew=181)
(1)证明:四面体
的外接球的体积为定值,并求出定值;
(2)若二面角
为直二面角,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95bacae35b6e16a0a33c2bdc6bc07df7.png)
![](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/6d93949d8a15aca4e79cedb978590571.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f0ac3005d5ecd6d4cea0ce99a47ef3c.png)
![](https://img.xkw.com/dksih/QBM/2017/4/21/1670758700146688/1672110284587008/STEM/b5aa502578c343d6a661ecd6b1878b14.png?resizew=181)
(1)证明:四面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f0ac3005d5ecd6d4cea0ce99a47ef3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1e6fd3e0bcc523ec7a8a6fcd2e4b239.png)
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解答题-问答题
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适中
(0.65)
【推荐2】如图,在直三棱柱
中,
分别为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/14/e1158db2-de0e-4633-b328-8c0cb403e03e.png?resizew=201)
(1)证明:直线![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
平面
;
(2)若
,求平面
与平面
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91e1e4115d78e625e9e0f47cdade3286.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5307e04a84a0621e4d5bd2aaa1980ef.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/14/e1158db2-de0e-4633-b328-8c0cb403e03e.png?resizew=201)
(1)证明:直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07b7903de4be7d5dc1175cfbf6e8da9f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1d40e591df390ac85e6857df821b5b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07b7903de4be7d5dc1175cfbf6e8da9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/152cfd5011c94e02c1a9cbbd4d8f58bb.png)
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适中
(0.65)
名校
【推荐3】如图,在
中,
,
,
分别为
的中点,
的延长线交
于
现将△
沿
折起,折成二面角
,连接
.
![](https://img.xkw.com/dksih/QBM/2011/2/9/1569979289100288/1569979294408704/STEM/32effbb86e494736b8c28dbac5e52eb1.png?resizew=214)
![](https://img.xkw.com/dksih/QBM/2011/2/9/1569979289100288/1569979294408704/STEM/1c5d68e9d3dc429297d10517e0dce84f.png?resizew=220)
(1)求证:平面
平面CBD;
(2)当
时,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f8f88798ec42a58dccd212586382b23.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ed8f7d3d7043d4b1eb98fc5c4e2fcd3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0769bbeb13bd66ee39f530417be0f92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91e1e4115d78e625e9e0f47cdade3286.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5c4cd264c97c1f261229925cc5a6761.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1bd1adfe4cc6566218f19970c2fd3b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af00a2603bb1c492527537d60949c76c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae4b97dd6e72a5ec06f44164a91b429f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca6d1c5eace748465b2dad5065f5111c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://img.xkw.com/dksih/QBM/2011/2/9/1569979289100288/1569979294408704/STEM/32effbb86e494736b8c28dbac5e52eb1.png?resizew=214)
![](https://img.xkw.com/dksih/QBM/2011/2/9/1569979289100288/1569979294408704/STEM/1c5d68e9d3dc429297d10517e0dce84f.png?resizew=220)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6501f1c913a4ef64957a2f01ab5baa15.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cfc1f76257275ab4b04f9bc913535670.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca6d1c5eace748465b2dad5065f5111c.png)
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