如图,直角三角形
中,
,沿斜边
上的高
,将
折起到
的位置,点
在线段
上.
![](https://img.xkw.com/dksih/QBM/2016/8/8/1572970456940544/1572970463264768/STEM/abdf6d23b46e47cf93fac111e4b9c86d.png)
(1)求证:
;
(2)过点
作
交
于点
,点
为
中点,若
平面
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94507394a55f53494bf44d5116f7a198.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da95ecece2225aeaa4fd2ea84dc61753.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ae08153d099dcdcae16194e2fffc0e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://img.xkw.com/dksih/QBM/2016/8/8/1572970456940544/1572970463264768/STEM/abdf6d23b46e47cf93fac111e4b9c86d.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93fb7b30592e38fb91f5342cd7a71849.png)
(2)过点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced90ea9183e02e54da78709e3cb9169.png)
![](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/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/28f79db7c270b6ff9fb0a538ee201cfe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/193b5b41994c2a4dfa5bb0bc984061cc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7558aa5068ceb3d3a35bf56422418dea.png)
更新时间:2016-12-04 18:39:30
|
【知识点】 证明异面直线垂直
相似题推荐
解答题-问答题
|
适中
(0.64)
【推荐1】如图,已知四棱锥
的底面
是正方形,侧棱
底面
.
![](https://img.xkw.com/dksih/QBM/2016/1/13/1572433164615680/1572433170612224/STEM/4c3eafc7d6ee4763b39ec1d57f59a6c1.png)
(1)若
,
是
的中点.证明:
平面
;
(2)若二面角
的余弦值为
,试求
的值.
![](https://img.xkw.com/dksih/QBM/2016/1/13/1572433164615680/1572433170612224/STEM/13dc5ab55742408f820b8c81829049b4.png)
![](https://img.xkw.com/dksih/QBM/2016/1/13/1572433164615680/1572433170612224/STEM/d5449102fa8e47479b30d2e2c8ba47e8.png)
![](https://img.xkw.com/dksih/QBM/2016/1/13/1572433164615680/1572433170612224/STEM/3ac4488fda7a49079a9482ad2fc23ecf.png)
![](https://img.xkw.com/dksih/QBM/2016/1/13/1572433164615680/1572433170612224/STEM/d5449102fa8e47479b30d2e2c8ba47e8.png)
![](https://img.xkw.com/dksih/QBM/2016/1/13/1572433164615680/1572433170612224/STEM/4c3eafc7d6ee4763b39ec1d57f59a6c1.png)
(1)若
![](https://img.xkw.com/dksih/QBM/2016/1/13/1572433164615680/1572433170612224/STEM/92b3af603b2f4ed580114218d251dfc2.png)
![](https://img.xkw.com/dksih/QBM/2016/1/13/1572433164615680/1572433170612224/STEM/683cd53d4c6d4f1e92795231da09d7a8.png)
![](https://img.xkw.com/dksih/QBM/2016/1/13/1572433164615680/1572433170612224/STEM/a5cdc90196bd4f169e84780eca076cfc.png)
![](https://img.xkw.com/dksih/QBM/2016/1/13/1572433164615680/1572433170612224/STEM/58e953e7d10b4f248ba691350d014eae.png)
![](https://img.xkw.com/dksih/QBM/2016/1/13/1572433164615680/1572433170612224/STEM/29a831d3c36743ba8209e4bebea6e549.png)
(2)若二面角
![](https://img.xkw.com/dksih/QBM/2016/1/13/1572433164615680/1572433170612224/STEM/8e733c889468424482919eb3e572f096.png)
![](https://img.xkw.com/dksih/QBM/2016/1/13/1572433164615680/1572433170612224/STEM/99b617f11beb40cbbe4a764c6dc933fb.png)
![](https://img.xkw.com/dksih/QBM/2016/1/13/1572433164615680/1572433170612224/STEM/86f9c1f4d9b44eac95c52765a95dfa9c.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2】如图,正方体
中,点
分别是
中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/14/7735a646-6cc2-442c-b855-a441ff06a424.png?resizew=196)
(1)求证:
;
(2)求
和平面
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7789a500686c7a73770404ead6af0590.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1427950aecc4709a5afe6722127c9a1f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/14/7735a646-6cc2-442c-b855-a441ff06a424.png?resizew=196)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2603fef52d4c7c20ec4628048515bc7a.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b8372f6eba66a0bd3587106daaf68d1.png)
您最近一年使用:0次