如图所示,空间多面体
中,
为正方形,
为梯形,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c399688f82087a8ed12cd4ac5c07dbb.png)
,且平面
平面
.
![](https://img.xkw.com/dksih/QBM/2021/1/12/2634620439855104/2637845906382848/STEM/6499fb86-05da-489d-958e-83684e2577b6.png?resizew=186)
(1)求证:
平面
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9165d9bfbb0f0d19eb482c2a4c1b29b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ecc1cb55a57dde481f8dd07ab150676.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c399688f82087a8ed12cd4ac5c07dbb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/28bc86e894faa9cd073fe9b455b3ff8b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9367449a5847eade07e69f4feddcb027.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/2021/1/12/2634620439855104/2637845906382848/STEM/6499fb86-05da-489d-958e-83684e2577b6.png?resizew=186)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e56fdf217165748fafe938b64fa08179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10fc7991ea17d54ff5f4445ac5699463.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/147310251a463539f66374c1f452fb67.png)
更新时间:2021-01-17 06:54:08
|
相似题推荐
解答题-证明题
|
适中
(0.65)
【推荐1】如图,平面
⊥平面
,四边形
是边长为
的正方形,
,
,
为
的中点,点
在线段
上.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/29/89698ca1-232a-47ea-ba18-27112e2ebb5f.png?resizew=167)
(1)求证:
平面
;
(2)若存在点
,使得平面
与平面
所成二面角的余弦值为
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10fc7991ea17d54ff5f4445ac5699463.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/347c8f892b0544ce1a5a0c7a8ab4bd64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6eba7e2cb2e2390673b83bde332973d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/29/89698ca1-232a-47ea-ba18-27112e2ebb5f.png?resizew=167)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8d2d217e9bcd059908f117dfc4d4259.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a09d9d486b7f91ba933210dd013a7f2c.png)
(2)若存在点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/408b6fc2d6cb101d75a407d9d4946a56.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a09d9d486b7f91ba933210dd013a7f2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/827ccf0c04aa941ba20d5f4c6068b46b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee355a26ee2a69305a1008725688a365.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
【推荐2】如图,在四棱锥
中,底面
是边长为2的正方形,侧面
是正三角形,平面
平面
.
![](https://img.xkw.com/dksih/QBM/2022/6/2/2992495409119232/2992871259111424/STEM/4f47e390-62f6-44c1-824e-4b1b68e77c95.png?resizew=186)
(1)证明:
平面
;
(2)求直线
与平面
所成角的正弦值;
(3)求点
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3520ee9cc97a075e889e1625dba1157c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://img.xkw.com/dksih/QBM/2022/6/2/2992495409119232/2992871259111424/STEM/4f47e390-62f6-44c1-824e-4b1b68e77c95.png?resizew=186)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f9157fce2a8339d281178c7c0bccbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3520ee9cc97a075e889e1625dba1157c.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e61620a272dada8d4b9a9fab6379dfd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/840798a31aba0783f96584e0ad7c0d2e.png)
(3)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/840798a31aba0783f96584e0ad7c0d2e.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
【推荐3】如图:在多面体
中,底面
是正方形,
,
.
底面
.
![](https://img.xkw.com/dksih/QBM/2022/4/11/2955971818848256/2957847891927040/STEM/f60b5ebc-3684-4952-8186-faf1f99908ce.png?resizew=180)
(1)证明:
平面
.
(2)求异面直线
与
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9165d9bfbb0f0d19eb482c2a4c1b29b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56d4ea87a0837c4eee99c8b5ba6ec977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56dd125a93bf6d5567753b059eec6a9b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a22d6b860f06fe23618b0d3de6768fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/2022/4/11/2955971818848256/2957847891927040/STEM/f60b5ebc-3684-4952-8186-faf1f99908ce.png?resizew=180)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e3c0430146b7b8d40ebb721a4d0de19.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6261790c66cc71ee3898afabad0c09f4.png)
(2)求异面直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐1】如图,正四棱台
有内切球
,且
.
(1)设平面
平面
,证明
平面
;
(2)求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23f919bd3dde10dbbc076f7ec5149699.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8862c0bfcaf3818565fee2f99cf2dfea.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/4/9/2715f3ff-1e6b-4a0d-9554-c02fcec36d0e.png?resizew=180)
(1)设平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/522da06a9cb494a1e4496273108b68af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c69861273f52724024c2bbf32f87c1bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23976db53f05b3d5d791c4d736a7184d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fb04914c4e8fb3483da44c67fe1809f.png)
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,O是圆柱下底面的圆心,该圆柱的轴截面是边长为4的正方形ABCD,P为线段AD上的动点,E,F为下底面上的两点,且
,
,EF交AB于点G.
时,证明:
平面CEF;
(2)当
为等边三角形时,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d38d97f03faed3152db2fd3bd1919944.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69babe5b1123f5e171c8845cbe4987c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdd03f8f2d904cbb8888188185956784.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbc6f007dbf1c1a36eb031e520608403.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91b51d3992644d37dc71c9b5a97d515c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29f8c417f5c19cc076dc6baeb0c173a9.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐3】如图1,在
中,
,D为
的中点,将
沿
折起,得到如图2所示的三棱锥
,二面角
为直二面角.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/31/a222f59a-e6d3-4565-8a9d-92e6ce9e501a.png?resizew=354)
(1)求证:
平面
;
(2)设
为
的中点,
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52d69f4a5fb68fb0170e394a78ea233f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab2a2834d80ff574e79eae8ca8d4e94f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08a9ec3b527947cad9caa4537e0cb7e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02a7ba7cd0c654714c967a900513ba16.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/31/a222f59a-e6d3-4565-8a9d-92e6ce9e501a.png?resizew=354)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ffc6952e988d04f22f0fb2f7f0ab7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f571a1aac46c6d0cf440c0ec2846bf9.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/75391dc7a2d0ca96f731e0ca2d6dd575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c539709f3b8449ef9cd00a86e194c099.png)
您最近一年使用:0次