如图,在正方体
中,
,
为
的中点,
是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/8/41b39a8a-4e0a-4fe1-9f32-f5f947dd2412.png?resizew=217)
(1)求证:平面
平面
;
(2)求证:
平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92535536bd3c2761724fd058427f95a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fe734023d4e70010a6b2cc3267cb86e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/8/41b39a8a-4e0a-4fe1-9f32-f5f947dd2412.png?resizew=217)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b55742a8c3d28853e5cc2a28cecafddf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e614ff5cf2702e4761cb4539ce19f71e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
更新时间:2016-12-04 02:25:53
|
相似题推荐
解答题-问答题
|
适中
(0.65)
名校
【推荐1】已知正方形
,E、F分别是边
的中点,将
沿
折起,如图所示,记二面角
的大小为
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/10/ae6a1496-fd11-4d5d-905c-34dd71697945.png?resizew=402)
(1)证明:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
平面
;
(2)若
为正三角形,证明点A在平面
内的射影G在直线
上,并求出
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c28d2790a97390935125aa897417f970.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51e231505648333857565accb0c3c898.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/798cdca7d20743e0197fe422f09fcbfe.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/10/ae6a1496-fd11-4d5d-905c-34dd71697945.png?resizew=402)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb31ef428bd9de9bc875b343feded3c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9a32bd7a1b78b5a0ec562c4025aea8c.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ac451db3443cabb204f96c31fd4a02e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fa7bbd7831e9ff4f8cffc8889d34f05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aefd06c239145a2b6ae87a955aa51414.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
解题方法
【推荐2】如图,四棱锥P﹣ABCD中,底面四边形ABCD是正方形,侧面PDC是边长为a的正三角形,且平面PDC⊥底面ABCD,E为PC的中点.
(1)求异面直线PA与DE所成的角的余弦值;
(2)求点D到面PAB的距离.
(1)求异面直线PA与DE所成的角的余弦值;
(2)求点D到面PAB的距离.
![](https://img.xkw.com/dksih/QBM/2011/8/4/1570279710097408/1570279715594240/STEM/3b73897d26084dc1b8a41f32fc8eb944.png?resizew=174)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐3】在四棱锥
中,四边形
是正方形,
平面
,
,E,F分别为棱
,
的中点.
(1)求证
平面
;
(2)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/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/98103ebb4fa6118eb6b91c09e7cf600e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/15/c7e2cca8-bb1c-46f4-bea7-4d9d4f3c674d.png?resizew=160)
(1)求证
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06222ee533c2484ab25321a6abbf98cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87c0bfeadcf17b2a45896071f07a4a5a.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
解题方法
【推荐1】如图,四棱锥
中,底面
为直角梯形,
∥
,
为等边三角形,平面
底面
,
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/4/1f541df5-3b31-4347-a8b1-cc474a3106e8.png?resizew=162)
(1)求证:平面
平面
;
(2)点
在线段
上,且
,求平面
与平面
所成的锐二面角的余弦值.
![](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/0ec534c945f61ca2130f8584b33bc512.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46725608d466cd5bad52b1c66cf8d91e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3da7bcea5a45eeae211f5851f12a7517.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/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/4/1f541df5-3b31-4347-a8b1-cc474a3106e8.png?resizew=162)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78a3fd5284e160896f07ce367645fd04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9068f29d671d76d1e95ba3a4eaff5b96.png)
(2)点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3160f7d57edbb1016dd1d2d17ad5a004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/013e58ab92ebfc889e2e0e2be903792e.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
解题方法
【推荐2】如图,已知圆锥的顶点为P,底面圆
的直径AB长为4,点C是圆上一点,
,点D是劣弧
上的一点,平面
平面
,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/21/d2732e5a-b0a6-4afa-8de8-fa4e48bb1e41.png?resizew=163)
(1)证明:平面
平面POD.
(2)当三棱锥
的体积为
时,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2bfb836792b1eebfbd08a6f46fae580e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/667349d99185bb045030b733352ff7fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c762937111e04018cad6b507a7dedc02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/baceb049bf16ed0fd33639fdda0ec5ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c29f3123f57b56444be9bc048eacc82.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/21/d2732e5a-b0a6-4afa-8de8-fa4e48bb1e41.png?resizew=163)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7392e9e2da5a0e9ecab0f79992656328.png)
(2)当三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b2a4541d85e8710408c45c99950b6af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d599cb4a589f90b0205f24c2e1fa021e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d0297943fae12e34fab38c541002b15.png)
您最近一年使用:0次