解题方法
1 . 在四棱锥P-ABCD中,底面ABCD是直角梯形,AB
CD,∠ABC=90°,AB=PB=PC=BC=2CD=2,平面PBC⊥平面ABCD.
(1)求证:AB⊥平面PBC;
(2)求三棱锥C-ADP的体积;
(3)在棱PB上是否存在点M,使CM
平面PAD?若存在,求
的值.若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895d6f710d5f67e1d4c7408d50d77281.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/4/4fc1c2ef-bc51-407d-97c8-7277426e28a6.png?resizew=165)
(1)求证:AB⊥平面PBC;
(2)求三棱锥C-ADP的体积;
(3)在棱PB上是否存在点M,使CM
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895d6f710d5f67e1d4c7408d50d77281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b505e0df1131e3a93fc81d13f6e224e7.png)
您最近一年使用:0次
2 . 如图,在四棱锥
中,
为正方形,且平面
平面
,点
为棱
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/25/00cf569b-09f9-4f61-b08f-abed9a03692e.png?resizew=184)
(1)在棱
上是否存在一点
,使得
平面
?并说明理由;
(2)若
,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/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/25/00cf569b-09f9-4f61-b08f-abed9a03692e.png?resizew=184)
(1)在棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8f70cf3f6c7acbf60d4a4ca0ce89619.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e6c2dad46a9052a4185a4f7b4ae8a2e.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa13ea01adb56b09930c077223a97522.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
您最近一年使用:0次