如图,在直三棱柱
中,
,
,
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/564517b02a6a50ff1ef6251d634530f8.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/8a07055c-85d6-4433-bc7d-9d04a23fbd3d.png?resizew=159)
(1)证明:当
时,求证:
平面
;
(2)当
时,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/615fc8790237a1b09af51d6bcad6b595.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/209acf15985d1ea1ad86fc4a37e38c0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e55a2310cbba5e050488cd9296eb195d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/564517b02a6a50ff1ef6251d634530f8.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/8a07055c-85d6-4433-bc7d-9d04a23fbd3d.png?resizew=159)
(1)证明:当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73b3cf0f585938ede9eca890a6eb326d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6d06903252260d31d1a9cdeb735b089.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8845fadc307f1d308410e829becedd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78ceb31247add8ca7b0853e801e1d125.png)
更新时间:2021-08-16 16:53:02
|
相似题推荐
解答题-证明题
|
适中
(0.65)
【推荐1】如图,
是正四棱柱.
![](https://img.xkw.com/dksih/QBM/2022/11/9/3105868343672832/3108191510528000/STEM/d492359f10ee4499848cc24aa89cb7bd.png?resizew=163)
(1)求证:
平面
;
(2)若二面角
的大小为
,求异面直线
与
所成角的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://img.xkw.com/dksih/QBM/2022/11/9/3105868343672832/3108191510528000/STEM/d492359f10ee4499848cc24aa89cb7bd.png?resizew=163)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a5928c98b341b16d4b5a5b931d2929d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9a8181f7a7fe7f3fac872ce9534f15.png)
(2)若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd190b5a26dfb45a06c1d6ee86dd82d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be6a6301878fed2a01413020b27310a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
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解答题-证明题
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适中
(0.65)
解题方法
【推荐2】P为正方形ABCD所在平面外一点,PA⊥面ABCD,AE⊥PB,求证:AE⊥PC.
![](https://img.xkw.com/dksih/QBM/2011/4/13/1570117697257472/1570117702549504/STEM/d72d8bd5-3051-4006-a27a-abb7d4c0ef13.png?resizew=177)
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解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐1】已知四棱锥
中,
平面
,底面
为菱形,
,E是
中点,M是
的中点,F是
上的动点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/23/91f3745f-3dcc-4437-b971-63d2a182fea7.png?resizew=175)
(1)求证:平面
平面
;
(2)直线
与平面
所成角的正切值为
,当F是
中点时,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05740f0c6071846227dc0ec177ad15e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/23/91f3745f-3dcc-4437-b971-63d2a182fea7.png?resizew=175)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6501f1c913a4ef64957a2f01ab5baa15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b46c607b3deac746c0ef3389ad8f65c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/839c7616cd0d90265f4b2c9c021254fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d01cca53693e4bc901899f3360d21618.png)
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解答题-证明题
|
适中
(0.65)
【推荐2】如图,已知直线
平面
,四边形
是梯形,四边形
为矩形,线段
交
于点N,
,点
为
中点,
.
![](https://img.xkw.com/dksih/QBM/2022/10/20/3091993794830336/3095133736050688/STEM/afce0af9ce674a169a5aa77722412826.png?resizew=247)
(1)求证:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
平面
;
(2)求二面角
的正弦值;
(3)在线段
上是否存在一点
,使得
与平面
所成角的正弦值为
,若存在,求出线段
的长;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13874df11ea939b4e3ff20787e4fa834.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a5bf51c07144386bd23a422d9ceb140.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51d04688a8cf6ffc8001e4bec41cac92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/655b6a742dbacdab5aaa298007663dd4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9faf1b5acbd346dc3b53a13904b66efc.png)
![](https://img.xkw.com/dksih/QBM/2022/10/20/3091993794830336/3095133736050688/STEM/afce0af9ce674a169a5aa77722412826.png?resizew=247)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f623667ca9e6ed42bb03431116992f71.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b82fc4fbb6fed1ce03056bf3bc04bdb4.png)
(3)在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00a28be4d5a16cf245f6fa7c4088fee4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69d2b798744645af88a4fa411344a83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1b489c25405ce48699d4f0a62820bed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57e25eb7b424a6866ea7bf1a995cc8f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d50703c46b6153945d718b198f03b4b5.png)
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