1 . 如图,在四棱锥
中,底面
是边长为
的正方形,
分别为
的中点,侧面
底面
,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/18/a59496fe-af17-4365-a9e8-8704410f3fbe.png?resizew=183)
(1)求证:
∥平面
,
(2)求证:直线
平面
,
(3)求证:平面
平面
.
![](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/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0ae9e915d670edaa52d9ad9f3f071a5.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/bb5363352988977cd5c38286b17a1097.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/18/a59496fe-af17-4365-a9e8-8704410f3fbe.png?resizew=183)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)求证:直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97f30533da2e1d2a958dc906c37eba9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(3)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
您最近一年使用:0次
11-12高二下·广西百色·阶段练习
2 . 如图,点P是正方形ABCD外一点,PA⊥平面ABCD,PA=AB=2,且E,F分别是AB,PC的中点.
(1)求证:EF//平面PAD;
(2)求证:EF
平面PCD;
(3)求:直线BD与平面
所成角的正弦.
(1)求证:EF//平面PAD;
(2)求证:EF
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1633988fd62a652de726ee92a917b52d.png)
(3)求:直线BD与平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6261790c66cc71ee3898afabad0c09f4.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/16/d5c39fff-980a-4162-bcf3-6e6e0ea43ebb.png?resizew=184)
您最近一年使用:0次
10-11高二下·广西南宁·期中
3 . 如图,几何体ABCDE中,△ABC是正三角形,EA和DC都垂直于平面ABC,且EA=AB=2a, DC=a,F、G分别为EB和AB的中点.
![](https://img.xkw.com/dksih/QBM/2011/5/5/1570179645661184/1570179650772992/STEM/f1e20a761916406292aa1b6f61cede73.png?resizew=161)
(1)求证:FD∥平面ABC;
(2)求证:AF⊥BD;
(3) 求二面角B—FC—G的正切值.
![](https://img.xkw.com/dksih/QBM/2011/5/5/1570179645661184/1570179650772992/STEM/f1e20a761916406292aa1b6f61cede73.png?resizew=161)
(1)求证:FD∥平面ABC;
(2)求证:AF⊥BD;
(3) 求二面角B—FC—G的正切值.
您最近一年使用:0次