如图,在棱长为1的正方体
中,点
在
上移动,点
在
上移动,
,连接
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/21/6197e44f-fa83-47e4-9c2f-7782a5fc6cb5.png?resizew=206)
(1)证明:对任意
,总有
平面
;
(2)当
时,求四面体
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83c09eec4e14a861af83d7828797d176.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/039d7699ed888e784646995d23061703.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/21/6197e44f-fa83-47e4-9c2f-7782a5fc6cb5.png?resizew=206)
(1)证明:对任意
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a3ce5abb6b25b37642d7322dcbe77cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edcf19a7f0dd0cdf59516ae585025110.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b54387f870ae37f7951b253665d64f6.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/759e6d90078d6d79e68c55e39e118d78.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/575c59ccfc4148fed7c4cd72bbabe3da.png)
更新时间:2020-03-15 21:40:38
|
相似题推荐
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐1】已知正方体
中,E是
的中点,
是
的中点.
平面
;
(2)设正方体的棱长为2,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22adbc0da438220f9cace11b629d799b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23f919bd3dde10dbbc076f7ec5149699.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cfbc0b5a8fbde804bd8425a4b76d207.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f11f1840eb8b17e7b07c3fe7e987a9c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c66d99a6a8415ddad22bbed33b64cfb.png)
(2)设正方体的棱长为2,求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9c31176e441852e88e002aa65a5923d.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】已知是棱长为
的正方体,
分别为棱
与
的中点,求四棱锥
的体积.
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解答题-证明题
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(0.65)
名校
【推荐3】如图,四棱锥
中,底面
是直角梯形,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b2050ced52081184a6ca55e166d9f3a.png)
平面PBC;
(2)已知
,
,
,若
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6be2b61f4a38e2ee2c1a01e00b3ae6c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b2050ced52081184a6ca55e166d9f3a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3d2bbf2309b4ff8599f57bca4203e90.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c07a898421b1752c9ad2293044cd42a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/445f7aff0e643af8435fe0676f366850.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4a3870ebb0a0e392da7947ac8c5d843.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/201caba8e53db5b7d7a64571afa48641.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e57d987e01ac3e624bfccfce94628562.png)
您最近一年使用:0次
解答题-证明题
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适中
(0.65)
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解题方法
【推荐1】如图,在四棱锥
中,底面ABCD是平行四边形,
,点E是PB的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/27/46147334-08a2-4aa4-86da-b1bd218b34b1.png?resizew=219)
(1)求证:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
平面EAC;
(2)若
,
,
,求点P到平面AEC的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cbb05b8b630052ff544249ebd72d95d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/27/46147334-08a2-4aa4-86da-b1bd218b34b1.png?resizew=219)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9bfa68259d7a331be323b2038d628a.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07d1fb184263d8ee5f5501162e516bb5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e7b6d04f024ca05cdfacc8ce9137c15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/799eb4b34586b807b0042aaa57ac5b84.png)
您最近一年使用:0次
解答题-证明题
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适中
(0.65)
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【推荐2】如图,在直三棱柱ABC-A1B1C1中,点O为A1B的中点,∠ABC=90°,AB=BC=2,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/15/688defb4-e20b-4f82-b2f7-ac2d9dee1404.png?resizew=133)
(1)证明:BC∥平面AOC1.
(2)求点B到平面AOC1的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f7e8dd831f4edc711c0f7d5f078f625.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/15/688defb4-e20b-4f82-b2f7-ac2d9dee1404.png?resizew=133)
(1)证明:BC∥平面AOC1.
(2)求点B到平面AOC1的距离.
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适中
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【推荐3】如图,在四棱锥
中,
平面
,
,点
在棱
上,
,点
,
是棱
上的三等分点,点
是棱
的中点.
,
.
∥平面
,且
,
,
,
四点共面;
(2)证明:平面
平面
;
(3)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5f1897a7e856b42f8cee0f286ad913d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a11029ca6b4b9e7f777af0280cf163c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47d669df6c391aa83150df5ae96c39d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/965ef11396a4dc720bab5589dc9c2fda.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11aba28f503a684a232490d37bcd3fd2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3064b70f24e9bbcab76e0dc61274b9b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09219dbd440c70d66bf2bf8b4c2bfe2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.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/895dc3dc3a6606ff487a4c4863e18509.png)
(2)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(3)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09219dbd440c70d66bf2bf8b4c2bfe2f.png)
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