如图,直三棱柱
中,侧面
是正方形,
侧面
,
,点
是
的中点.
![](https://img.xkw.com/dksih/QBM/2018/2/12/1880868797218816/1882376916418560/STEM/e3280a54f25344e7913585434cb239f9.png?resizew=131)
(1)求证:
//平面
;
(2)若
,垂足为
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9edc50f7febbc2d5d8dcdc23a3630a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e56fdf217165748fafe938b64fa08179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9edc50f7febbc2d5d8dcdc23a3630a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d384390f4e0a1e0abd4cc19382d94db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56f7ba05c54b3de1f4378f7c8eb58328.png)
![](https://img.xkw.com/dksih/QBM/2018/2/12/1880868797218816/1882376916418560/STEM/e3280a54f25344e7913585434cb239f9.png?resizew=131)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4df5845bc756fe9d1a8af6bb56fcc36.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f862cc67a19626347f9946703017d8b.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b0cb50d335fb0018c499de301fc3aac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/580662f123ff7898cdb9ae94b9d52b3b.png)
更新时间:2018-02-14 22:08:33
|
相似题推荐
解答题-证明题
|
适中
(0.65)
【推荐1】如图,在三棱锥P-ABC中,PA=PB=AB=2,BC=3,∠ABC=90°,平面PAB⊥平面ABC,D、E分别为AB、AC中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/1/726dd93d-b665-4005-a50f-5173822377c7.png?resizew=194)
(1)求证:
平面PBC;
(2)求证:AB⊥PE;
(3)求二面角A-PB-E的大小.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/1/726dd93d-b665-4005-a50f-5173822377c7.png?resizew=194)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7440b41636c761b0910639e310ff7dfb.png)
(2)求证:AB⊥PE;
(3)求二面角A-PB-E的大小.
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,在四棱锥P-ABCD中,底面ABCD是边长为2的菱形,∠ABC=60°,△PAB为正三角形,且侧面PAB⊥底面ABCD,E为线段AB的中点,M在线段PD上.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/21/9368cdd9-fb62-4316-99a3-1c8c0c256f89.png?resizew=171)
(1)当M是线段PD的中点时,求证:PB∥平面ACM;
(2)求证:PE⊥AC.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/21/9368cdd9-fb62-4316-99a3-1c8c0c256f89.png?resizew=171)
(1)当M是线段PD的中点时,求证:PB∥平面ACM;
(2)求证:PE⊥AC.
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐1】如图,在三棱柱ABC-A1B1C1,中,B1B上平面A1B1C1,AC=CB=CC1=2,∠ACB=90°,D,E分别是A1B1,CC1的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/3dbe5b22-9fb6-4562-b30e-e2fd75f1037c.png?resizew=155)
(1)求证:平面A1BE上平面AA1B1B;
(2)求直线BC1与平面A1BE所成角的正弦值.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/3dbe5b22-9fb6-4562-b30e-e2fd75f1037c.png?resizew=155)
(1)求证:平面A1BE上平面AA1B1B;
(2)求直线BC1与平面A1BE所成角的正弦值.
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐2】如图,在四棱锥
中,平面
平面
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/28/e17d9f5d-b9de-4052-a288-c1ec4859c9df.png?resizew=201)
(1)求证:
平面
;
(2)若直线
与底面
所成的角的正切值为
,求二面角
的正切值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78a3fd5284e160896f07ce367645fd04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5799e67a7f6ef3e0e1ec46aa0ee4c0c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7856b06682c9058d76120982fdbc91c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/28/e17d9f5d-b9de-4052-a288-c1ec4859c9df.png?resizew=201)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97f30533da2e1d2a958dc906c37eba9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f571a1aac46c6d0cf440c0ec2846bf9.png)
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95bacae35b6e16a0a33c2bdc6bc07df7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/290a37874cd284fb1a8c864769ce50c9.png)
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