如图,在四棱锥P-ABCD中,底面ABCD为菱形,∠BAD=60°,Q为AD的中点.
![](https://img.xkw.com/dksih/QBM/2018/2/26/1890692452900864/1894008651808768/STEM/353db6c2354f4a7497cfd3c15f0dc782.png?resizew=146)
(Ⅰ)若PA=PD,求证:平面PQB⊥平面PAD;
(Ⅱ)点M在线段PC上,PM=tPC,试确定实数t的值,使PA∥平面MQB;
(Ⅲ)在(Ⅱ)的条件下,若平面PAD⊥平面ABCD,且PA=PD=AD=2,求二面角M-BQ-C的大小.
![](https://img.xkw.com/dksih/QBM/2018/2/26/1890692452900864/1894008651808768/STEM/353db6c2354f4a7497cfd3c15f0dc782.png?resizew=146)
(Ⅰ)若PA=PD,求证:平面PQB⊥平面PAD;
(Ⅱ)点M在线段PC上,PM=tPC,试确定实数t的值,使PA∥平面MQB;
(Ⅲ)在(Ⅱ)的条件下,若平面PAD⊥平面ABCD,且PA=PD=AD=2,求二面角M-BQ-C的大小.
更新时间:2018-03-03 08:33:22
|
【知识点】 面面角的向量求法
相似题推荐
解答题-证明题
|
适中
(0.65)
名校
【推荐1】如图,在三棱柱
中,
平面
是棱
的中点,
在棱
上,且
.
平面
;
(2)若四棱锥
的体积等于1,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5845ccc0d735dc14c92a8926d9b1def6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/044c0786ea53dd21587183ff4cc41e6b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adad77d896c9ac008a6832f10079ec2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f306ff6d237cd9d847aa109acf9333d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db3ef97d64e58d311019b70fe5e2cc0d.png)
(2)若四棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f2a3e382df99954c1d787d11af0d049.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46063cbdc5f15455de4728fac3e1228e.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】已知正方形
的边长为4,点
为边
上一点,将
沿着
折起,使
点到
的位置,此时
点在平面
内的射影在
上,且
.
(1)求
点到平面
的距离;
(2)求二面角
的大小.
![](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/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5b3bd5e6bc2a0a277d279bb01af9584.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5b3bd5e6bc2a0a277d279bb01af9584.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/71e754301c85b15035c2b36a6dc8b68a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/20/5c272f30-626d-4189-93a5-bf8ad96190fc.png?resizew=173)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5b3bd5e6bc2a0a277d279bb01af9584.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4c35e8cf7b77cda3a23aaca62cd937f.png)
您最近一年使用:0次