如图,在直三棱柱
中,
,
,M为AB的中点,D在
上且
.
![](https://img.xkw.com/dksih/QBM/2021/11/1/2841884274384896/2845020000722944/STEM/a627901f-0fcf-46f1-ad6d-11af03167f2d.png?resizew=218)
(1)求证:面
面
;
(2)求面CBD与面ABC的夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/177f0adc6666014e717ef2381ea27fb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5355da4203567ad145f6fabd226405a0.png)
![](https://img.xkw.com/dksih/QBM/2021/11/1/2841884274384896/2845020000722944/STEM/a627901f-0fcf-46f1-ad6d-11af03167f2d.png?resizew=218)
(1)求证:面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/268be8b7f83cbdf253b1e05e09cbbad7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
(2)求面CBD与面ABC的夹角的余弦值.
更新时间:2021-11-05 23:50:55
|
相似题推荐
解答题-证明题
|
适中
(0.65)
解题方法
【推荐1】如图所示,三棱柱
中,
平面
,
,点M,N分别是线段
,
的中点,求证:
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/29/2f241e16-7c61-437b-8e25-a131a54b0703.png?resizew=145)
(1)平面
平面
;
(2)
∥平面
.
![](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/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45acdbac251ca6b76a166c1242e71df9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/29/2f241e16-7c61-437b-8e25-a131a54b0703.png?resizew=145)
(1)平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91a2712f9cc643d4983d37c9dfe880ec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f96c673a2381f118ea2d3efc0bca1f3.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee16c91119c5601a7c93a6642c95e7f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3653ada76ba0c8afe9d57c8e7832c6ed.png)
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名校
解题方法
【推荐2】如图,在矩形
中,
,点
是
的中点.将
沿
折起,使得点
到达点
的位置,且使平面
平面
.
![](https://img.xkw.com/dksih/QBM/2020/7/22/2511303048527872/2511948913696768/STEM/4702ce6c86ce4cd28eb0816ee3252837.png?resizew=227)
(1)求证:平面
平面
;
(2)求平面
与平面
所成锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c4e4a162f12d12a082b8d8fdd1aeab9.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/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90d96357a07048ba79b8c84097d359d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01ff27eea7545bb06f9472f91290c54e.png)
![](https://img.xkw.com/dksih/QBM/2020/7/22/2511303048527872/2511948913696768/STEM/4702ce6c86ce4cd28eb0816ee3252837.png?resizew=227)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a26a7784c7419d8359fb119c8ecc03d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e6c2dad46a9052a4185a4f7b4ae8a2e.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e6c2dad46a9052a4185a4f7b4ae8a2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1b489c25405ce48699d4f0a62820bed.png)
您最近一年使用:0次
解答题-问答题
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适中
(0.65)
【推荐1】如图,在四棱锥
中,底面
是矩形,
平面
,
分别是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/29/5d28ea3c-93c0-4804-99b9-a19ccef4d713.png?resizew=180)
(1)证明:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
平面
;
(2)若直线
与平面
所成的角为
,求平面
与平面
夹角的余弦值.
![](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/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c34a31b55d1720114ed7c617fc76b2d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1457d2e76a5b86de1abf121c51eb9d35.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/29/5d28ea3c-93c0-4804-99b9-a19ccef4d713.png?resizew=180)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895d6f710d5f67e1d4c7408d50d77281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec1dcba40b263c1119ea0a36651c7812.png)
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1e5fa72f2878b476bc57f0df12d6555.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec1dcba40b263c1119ea0a36651c7812.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d246f9eceab371ebf47a47c2f11a4ad.png)
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名校
【推荐2】如图,
是一个四棱锥,已知四边形
是梯形,
平面
,
,
,
,
,点
是棱
的中点,点
在棱
上,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/28/313f396a-4920-4d00-96d5-ea90343b14c7.png?resizew=199)
(1)证明:直线
平面
;
(2)求直线
与平面
所成角的正弦值;
(3)求平面
与平面
的夹角的余弦值.
![](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/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdb2dd10731b99c0f4f89ee957f8a239.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10df84d553a8826a7ce9bff4bf0d95b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ada16b1abf359ee1c6edb056aa7f510a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/833cfda415649b832cc136caed392753.png)
![](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/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11001bd2378b5b7bdef96cb9deab274b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/28/313f396a-4920-4d00-96d5-ea90343b14c7.png?resizew=199)
(1)证明:直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7175df06e33cad4e6bbc3f2f6b0a2986.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f571a1aac46c6d0cf440c0ec2846bf9.png)
(3)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
您最近一年使用:0次
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【推荐3】如图,四棱锥
中,底面
是矩形,
,
,且侧面
底面
,侧面
底面
,点F是PB的中点,动点E在边BC上移动,且
.
(1)证明:
底面
;
(2)当点E在BC边上移动,使二面角
为
时,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13ff5ff92f2505a933d0213039f4c014.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbb24da8242d2c143ddbd9bbdc7dda87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.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/725ce6635389e73a507383151b62e898.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/9/f32c763e-04af-475f-8f2f-eb38bd75fb41.png?resizew=150)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)当点E在BC边上移动,使二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37de2f75ae1fa56a52f1e52d624c6dd2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d5bca00fa20e6e80480b9d06d2e52ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ee9a87e271f046855634f1347cc1cde.png)
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