如图,菱形
的中心为
,四边形
为矩形,平面
平面
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4023f83ce8a6eb503c396387dfbd0dd.png)
(1)若
为
的中点,求证:
平面
;
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/2/7f715ebd-7fa2-45cc-9bd3-704bf3576420.png?resizew=204)
(2)若
,求二面角
的余弦值.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/2/1bdfc423-ca64-4858-85d6-d6879ba0a12d.png?resizew=204)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c10f93679abcee21bacd92c3b1552a0e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6fd3eb54b28d8c2f322ea6e32255832.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4023f83ce8a6eb503c396387dfbd0dd.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1399e7ae0b2decaafc62a5cdffb15522.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a09d9d486b7f91ba933210dd013a7f2c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/2/7f715ebd-7fa2-45cc-9bd3-704bf3576420.png?resizew=204)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa2d865f65952e6b7674073d29163317.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/907cbb8368c439429946651c7b075baf.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/2/1bdfc423-ca64-4858-85d6-d6879ba0a12d.png?resizew=204)
更新时间:2017-10-07 18:49:50
|
相似题推荐
解答题-证明题
|
适中
(0.65)
解题方法
【推荐1】如图,在四棱锥A-BCDE中,四边形BCDE为菱形,
,
,AE=AC,点G是棱AB上靠近点B的三等分点,点F是AC的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/5/15bb81dc-e470-4736-9b01-326bf8a68c42.png?resizew=204)
(1)证明:
∥平面CEG.
(2)点H为线段BD上一点,设
,若AH⊥平面CEG,试确定t的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57c6b0a6cb307c4c02f503831862f7d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1719410d21e3de1242366ce2965e838c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/5/15bb81dc-e470-4736-9b01-326bf8a68c42.png?resizew=204)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
(2)点H为线段BD上一点,设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad0fe35910d0c4e31064930f0e672991.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】在三棱柱
中,侧棱与底面垂直,
,
,
,点
是
的中点.
(1)求证:
平面
;
(2)求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d70dc2c20619a4fc12a0cfda59af5b69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e65a3e478bb87d094e3a0af30dd10ae8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f08273d339dc5ddbb89aa67bb8205e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4557a368725226f2c8ea2efb7d30e478.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbc7e774e4ae40c23bf4ceed179230ca.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b4cdc3a083d1263634d510f172dab09.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,五面体
中,
,平面
平面
,平面
平面
,
,
,点
是线段
上靠近
的三等分点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/30/d0c53633-67f9-40f5-ae16-673fb83250af.png?resizew=206)
(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/9165d9bfbb0f0d19eb482c2a4c1b29b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2eca28c61c2ed413091fe1c106248a2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/393a753b57da192086a617f26ec89aea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/369eb8ad56da7dc1cdb7c43762be4bee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec2af539ca4fdc2fa94d4986537b6598.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/369eb8ad56da7dc1cdb7c43762be4bee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3989e6ca53493f203e146127341b9ff4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/666734423f1818d76a74f171b7420b68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/30/d0c53633-67f9-40f5-ae16-673fb83250af.png?resizew=206)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eaf9403ecd2ae90269297499ba6c7182.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/603c7e98deecdba0cf3773757a9b8304.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fd17a66a2af938c89e46f22e4d893b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4734735213b599a9915e1ed91a5d8ce4.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
【推荐1】在如图所示的几何体中,
,
,
均为等边三角形,且平面
平面
,平面
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/2/31a287ea-e383-40bb-b591-1eb9573fa4de.png?resizew=206)
(1)证明:
;
(2)若
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcb49df05f2e31d005735c3f14a21d30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/661ff55b5ebbadfb600989af3cfce2fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8dc6db50a9709c3f4d84eee7bdf1250.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c309e58bf083bad13abd549720a63a22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/2/31a287ea-e383-40bb-b591-1eb9573fa4de.png?resizew=206)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ebe7eaf967808dad0a184eeedfa27721.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1e52b5625cff6fc8c5e150dd02a6e4b.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】如图,四边形
是平行四边形,且
,四边形
是矩形,平面
平面
,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/24/2cde64b6-ddc9-4bce-9dd3-07eb53033121.png?resizew=177)
(1)求证:
平面
;
(2)求平面
与平面
所成的锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e35225f4d153a40ff5a6485590805a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd4b93d7abcfc4c3df48f03aa969c17f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2a4e3f0349fa83dc2a0b7d798f04843.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22437a2a3402609bfd4054a9f2b6c685.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/24/2cde64b6-ddc9-4bce-9dd3-07eb53033121.png?resizew=177)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca5dd496ee0c1170ef6dcc48266ee444.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6541c0cb89f08aa4c937c0beb915e0a7.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87c0bfeadcf17b2a45896071f07a4a5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10fc7991ea17d54ff5f4445ac5699463.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐3】如图所示,四棱锥
中,侧面
是边长为
的正三角形且与底面垂直,底面
是
的菱形,
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/1/4663ace5-1124-4c04-a88c-93f1779ec762.png?resizew=220)
(1)求
与底面
所成角的大小;
(2)求证:
平面
;
(3)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/218054144a13435580cd132b9459546c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c161375e4e6f61f1cbef8083c02e975.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/1/4663ace5-1124-4c04-a88c-93f1779ec762.png?resizew=220)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cfe67036b4671b5d2a5c55b48c4d3bb9.png)
(3)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4643f8e7ed4155ad5b677101b477279c.png)
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