如图,在三棱柱
中,侧面
为边长为
的菱形,侧面
为矩形,其中
且
,
平面
,点
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/24/c80cde80-f477-47d7-84ef-a9881390430d.png?resizew=122)
(1)证明:
平面
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcb84cc7d5f7b10fac5fe3183c649a9b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/878e89b6eca35e34c863e832a2c661db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ecc1cb55a57dde481f8dd07ab150676.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff97f162adb9639f524999989b1fb949.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e075468e7fb0bf30229aec01a7205977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a22d6b860f06fe23618b0d3de6768fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/24/c80cde80-f477-47d7-84ef-a9881390430d.png?resizew=122)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ffc6952e988d04f22f0fb2f7f0ab7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73153657848013d2a1c3247d7f84ddeb.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adef2eaf43d5af6e27d779533b26f461.png)
更新时间:2020-07-10 09:30:04
|
相似题推荐
解答题-证明题
|
适中
(0.65)
名校
【推荐1】如图,在四棱锥
中,平面
平面
,
分别为
的中点.
(1)证明:
平面
;
(2)若
与
所成的角为
,求平面
和平面
夹角的余弦值.
![](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/29d7e1b1a46b1a26e146fe7a60349353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d1af79f56187b8629bc0c599fb2dcc7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2682f3f3f0f72c893b99073bcac83ff2.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/31/5d1764b2-4d24-4b8b-93de-5bdcc4649c27.png?resizew=190)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ffc6952e988d04f22f0fb2f7f0ab7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64eb31601464364be2baf4aa87404bcd.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be6a6301878fed2a01413020b27310a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87c0bfeadcf17b2a45896071f07a4a5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c09afc70f448545336304333d5b5658b.png)
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解答题-问答题
|
适中
(0.65)
解题方法
【推荐2】如图1,圆O的内接四边形
中,
,
,直径
.将圆沿
折起,并连接
、
、
,使得
为正三角形,如图2.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/2/fa1e9412-2c55-4d83-a859-a32d01660735.png?resizew=289)
(1)证明:图2中的
平面
;
(2)在图2中,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32ed407cbb778f76bf879bfcae69ebba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c646c683fbe522edb7ea54fd3ad873d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bb5b12692517a39c320f99a479eb055.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b90e0f35eda1a729fed485f83da5ea9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/683c590673eece14fea3319c4fd5eb55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4686f39b38d5b90309ee73ed89a0640.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/2/fa1e9412-2c55-4d83-a859-a32d01660735.png?resizew=289)
(1)证明:图2中的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f9157fce2a8339d281178c7c0bccbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
(2)在图2中,求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d63a158f3cd698827a5099a09ba6d7e.png)
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适中
(0.65)
名校
【推荐1】如图,在长方体
中,
,点
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/18/4876b939-a692-480e-84a0-45cb19bae089.png?resizew=130)
(1)证明
;
(2)求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f01b20705a4d59b6ab59011fd8c6ecd1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22adbc0da438220f9cace11b629d799b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/18/4876b939-a692-480e-84a0-45cb19bae089.png?resizew=130)
(1)证明
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59035a84a2bedd293453b419d36eca86.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74bca84ad86c648d3bb20c8909c8da3f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fae7f4612c548b1f72a964ddb291cd2e.png)
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适中
(0.65)
解题方法
【推荐2】已知正方体
的棱长为1,求点B到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b0a582c36d62d83c16425b2f54b4354.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐1】如图,在正三棱柱
中,D为棱
上的点,E,F,G分别为
,
,
的中点,
.
![](https://img.xkw.com/dksih/QBM/2022/3/24/2943024912302080/2943173408899072/STEM/5d9d6b1e3df74e6882ec0fc8fa23ec86.png?resizew=290)
(1)求证:
;
(2)若![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c63e36329f5e0979f5ee776ac5d06327.png)
平面
,试确定D点的位置,并求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c9d5815dc775d5a5810fff0b016a8d5.png)
![](https://img.xkw.com/dksih/QBM/2022/3/24/2943024912302080/2943173408899072/STEM/5d9d6b1e3df74e6882ec0fc8fa23ec86.png?resizew=290)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ce1335e489c2b0835d7e16ea765e1e9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c63e36329f5e0979f5ee776ac5d06327.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9bfa68259d7a331be323b2038d628a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e59b1f7689bff6644bfdeb9e36feb163.png)
您最近一年使用:0次
解答题-问答题
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适中
(0.65)
解题方法
【推荐2】如图,在正四棱锥
中,底面正方形的对角线AC,BD交于点O,
,
.求:
的大小;
(2)点B到平面CDP的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9934cf2feb65b00392ba39d8242e47.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/caa431d661bf9f419e8ab713dd4a3c80.png)
(2)点B到平面CDP的距离.
您最近一年使用:0次