在四棱锥
中,
平面
,底面
为正方形,
,E和F分别为
和
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/3/97e305e8-d789-4b54-a36b-cb69e8b2f3c5.png?resizew=165)
(1)证明:
平面
;
(2)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/829f9180ddd9aa1a0ee0dc520f4e0b5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/3/97e305e8-d789-4b54-a36b-cb69e8b2f3c5.png?resizew=165)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57f9d682e5d3cc8573574d8d11636758.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b28b5b7b3ce8cfd88c3428883bd0852e.png)
更新时间:2023-04-27 13:06:13
|
相似题推荐
解答题-问答题
|
适中
(0.65)
名校
解题方法
【推荐1】在①
是
边上的高,且
,②
平分
,且
,③
是
边上的中线,且
这三个条件中任选一个,补充在下面的问题中,并求出边
的长.
问题:在锐角
中,已知
,
,
是边
上一点,_____,求边
的长.
注:如果选择多个条件分别解答,按第一个解答计分
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9ab42c7f0a7102ade314f5962a62f1e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f093f755047ec741fdd445ec4659ffe7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/689790717d7fb3a510987f36f83c23b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
问题:在锐角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d70dc2c20619a4fc12a0cfda59af5b69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
注:如果选择多个条件分别解答,按第一个解答计分
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
【推荐2】已知
中,角
,
,
的对边分别为
,
,
,若
,且
,
.
(Ⅰ)求
的长;
(Ⅱ)求
的值;
(Ⅲ)求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e5bfa8dffc0052e575f40103ef640fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcdb7a488910743dc5c63afb394b87e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ceba46526c1a7df5929c00cd257dba3c.png)
(Ⅰ)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
(Ⅱ)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/721e29b775e696045f44a4b1e7f74ef2.png)
(Ⅲ)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5890a5a90c859b134b4dd611b6cf2ed.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】在如图所示的六面体中,四边形
是边长为2的正方形,四边形
是梯形,
,平面
平面
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/6/e983fd68-398b-48ac-891d-71ad08a927e8.png?resizew=185)
(1)求证:
平面
;
(2)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd3e927b7b2383ccded03838ae8b30b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cf9a6db3571fa57bfa2d5e4d44c51b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49282ee0fe94e4c25ffaabf419ea83b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68004768b879c6a052f45a2c45217cd6.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/6/e983fd68-398b-48ac-891d-71ad08a927e8.png?resizew=185)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8197bf06d017950c85c3ba6a291c095e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2977ae4bfa32de8c6f0fb136205c4fe7.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,在四棱锥
中,底面ABCD是直角梯形,侧棱
底面ABCD,AB垂直于AD和BC,M为棱SB上的点,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/23/3508b880-f5c3-4dea-89d5-6f3d6656e055.png?resizew=174)
(1)若M为棱SB的中点,求证:
平面SCD;
(2)当
,
时,求平面AMN与平面SAB所成的锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10c83f8945042b9c8fb2fbdac9308d62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c545f94200a27e96baa417662dc3f1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef0402dd5ae3db10281f9f1e11738bcb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f4aca5534bce25acaeb7379deed8f8f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/23/3508b880-f5c3-4dea-89d5-6f3d6656e055.png?resizew=174)
(1)若M为棱SB的中点,求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ac480d8d9d7821b62a603cf5cfda236.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24565d8d2842481818f96cf52962c50d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f899a80d5d287807b8db5067a6edeec.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】如图几何体是圆锥的一部分,它是Rt△ABC(及其内部)以一条直角边AB所在直线为旋转轴旋转150°得到的,AB=BC=2,P是弧
上一点,且EB⊥AP.
![](https://img.xkw.com/dksih/QBM/2020/1/13/2376306543706112/2422032537239552/STEM/fb28e887-8993-453a-9faf-95b326072086.png)
(1)求∠CBP的大小;
(2)若Q为AE的中点,D为弧
的中点,求二面角Q﹣BD﹣P的余弦值;
(3)直线AC上是否存在一点M,使得B、D、M、Q四点共面?若存在,请说明点M的位置;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3839ab58dabbf4c12ee69770bdbf8dac.png)
![](https://img.xkw.com/dksih/QBM/2020/1/13/2376306543706112/2422032537239552/STEM/fb28e887-8993-453a-9faf-95b326072086.png)
(1)求∠CBP的大小;
(2)若Q为AE的中点,D为弧
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67a4fdec4ee1fc83fdd6b4c324755d95.png)
(3)直线AC上是否存在一点M,使得B、D、M、Q四点共面?若存在,请说明点M的位置;若不存在,请说明理由.
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐2】如图所示,在正三棱柱
中,底面边长为
,侧棱长为
,
是棱
的中点.
![](https://img.xkw.com/dksih/QBM/2010/5/29/1569750320005120/1569750325248000/STEM/88b9185b052843cc94f5cbf1cf15ed50.png)
(Ⅰ)求证:
平面
;
(Ⅱ)求二面角
的大小;
(Ⅲ)求点
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57f47d6a88e962cd790d2f159c021ec1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b234f945df3ebb9fe5e3e903fad696b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://img.xkw.com/dksih/QBM/2010/5/29/1569750320005120/1569750325248000/STEM/88b9185b052843cc94f5cbf1cf15ed50.png)
(Ⅰ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f5830646a912c3a916beac4f88c116b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5888bec948373f3854258ad80171073d.png)
(Ⅱ)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51a78cc38c9df701d6efb6e9b707cd3d.png)
(Ⅲ)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1241216f3c1cb5e73043dd1037f556d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5888bec948373f3854258ad80171073d.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐3】如图,已知二面角
,且
,
,
,C,D是垂足,平面PCD与AB交于点H.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/29/a178b3d6-6f06-4bbe-91d1-04b5a60fa5d1.png?resizew=245)
(1)求证:AB⊥平面PCD;
(2)若PC=PD=CD=1,试求二面角
的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79ce3f859c6b9a0cfc98bdf5b3d0f395.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74742135157ce66703f899d52748b78b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d9105f139c37c74dcab39b136c267eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf90b31eb064a12d3ed6bffaaccc8737.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/29/a178b3d6-6f06-4bbe-91d1-04b5a60fa5d1.png?resizew=245)
(1)求证:AB⊥平面PCD;
(2)若PC=PD=CD=1,试求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79ce3f859c6b9a0cfc98bdf5b3d0f395.png)
您最近一年使用:0次