如图,四棱锥
中,底面是以
为中心的菱形,
底面
,
,
为
上一点,且
.
(1)求
的长;
(2)求二面角
的正弦值.
![](https://img.xkw.com/dksih/QBM/2014/6/20/1571784957353984/1571784963276800/STEM/c2f70fe100034862ad6a8d5165d3db75.png)
![](https://img.xkw.com/dksih/QBM/2014/6/20/1571784957353984/1571784963276800/STEM/9874f5fd78824379bc461e831765222c.png)
![](https://img.xkw.com/dksih/QBM/2014/6/20/1571784957353984/1571784963276800/STEM/666341487fc24fe894dd5693b5423d70.png)
![](https://img.xkw.com/dksih/QBM/2014/6/20/1571784957353984/1571784963276800/STEM/c285cf021e4146ea9257c0acf215d626.png)
![](https://img.xkw.com/dksih/QBM/2014/6/20/1571784957353984/1571784963276800/STEM/5e24b055d96e44bfb1379179ae66437d.png)
![](https://img.xkw.com/dksih/QBM/2014/6/20/1571784957353984/1571784963276800/STEM/e8e14784d9d94c5298c601d73e447b85.png)
![](https://img.xkw.com/dksih/QBM/2014/6/20/1571784957353984/1571784963276800/STEM/a83d9b34c6924cca9a9813d7d0411cf1.png)
![](https://img.xkw.com/dksih/QBM/2014/6/20/1571784957353984/1571784963276800/STEM/0b2dbced52bc4937b20069a722f436af.png)
(1)求
![](https://img.xkw.com/dksih/QBM/2014/6/20/1571784957353984/1571784963276800/STEM/542f6e6aab214cde92cb47df27649862.png)
(2)求二面角
![](https://img.xkw.com/dksih/QBM/2014/6/20/1571784957353984/1571784963276800/STEM/e480f142b1dd41fd9ababe1b594f8627.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/10/c5a93352-2096-4256-abb2-0c6023565c6a.png?resizew=218)
更新时间:2016-12-03 02:27:36
|
【知识点】 面面角的向量求法
相似题推荐
解答题-证明题
|
较易
(0.85)
名校
【推荐1】如图,四边形
是正方形,
平面
,
,
,
分别为
的中点.
平面
;
(2)求平面
与平面
夹角的大小;
(3)求点
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97587226682cfc4f4469b9376dd83853.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f45ea9d4410e9926c592fa0a9dfac97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7a8f3a13cb258c61e2a221c2bf09979.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69b0a17570e1e3caeaeca8a5061da677.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aee6b8fbf4ad75d75ab4aa7f39e61a9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b37793a3a810e823e10c340986f55ddd.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1828e73ec5e00f95aa11ff74c703a5c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(3)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
您最近一年使用:0次
解答题-证明题
|
较易
(0.85)
名校
解题方法
【推荐2】如图所示的几何体中,
是菱形,
,
平面
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/7/a2444e55-cb5d-4ba7-860d-5c530e173051.png?resizew=180)
(1)求证:平面
平面
;
(2)求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e075468e7fb0bf30229aec01a7205977.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/ab2addb6ef9ede5e234f4b363f5dc0e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57dfec4b826f33d0fd5e9664f52ae2fa.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/7/a2444e55-cb5d-4ba7-860d-5c530e173051.png?resizew=180)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d077f6da8b2c00b152d4679aa2ed7f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9068f29d671d76d1e95ba3a4eaff5b96.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db04e82f03e6216886d416b35abe85a3.png)
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