在四棱锥
,
平面ABCD,PA=2.
![](https://img.xkw.com/dksih/QBM/2015/3/26/1572034495954944/1572034501705728/STEM/10c6648844a545d6b8b5dcbdfc28c228.png)
(I)设平面
平面
,求证:
;
(II)设点Q为线段PB上一点,且直线QC与平面PAC所成角的正切值为
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54df3899ec44310cc91ce5033890d617.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e2f5b2d5fcd04b4ddc73a0dc600ced9.png)
![](https://img.xkw.com/dksih/QBM/2015/3/26/1572034495954944/1572034501705728/STEM/10c6648844a545d6b8b5dcbdfc28c228.png)
(I)设平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ebb72da110242e9fa3272e75fe82363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57c3a39145348a7f92fde1fddc05ea8b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96ebf94f30c42ae2fb65d19177e00b8a.png)
(II)设点Q为线段PB上一点,且直线QC与平面PAC所成角的正切值为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d5989c84e320b504511f23eeb6e7357.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/450613b1e166a71f8c17c93f7dcbab97.png)
更新时间:2016-12-03 10:55:17
|
相似题推荐
解答题-证明题
|
适中
(0.65)
名校
【推荐1】如图在三棱锥
中,点
,
,
,
分别为相应棱的中点,
![](https://img.xkw.com/dksih/QBM/2020/10/30/2582361868599296/2582829679149056/STEM/d8f69c07-c44e-4b6f-920b-38a2af2fb426.png?resizew=224)
(1)求证:四边形
为平行四边形.
(2)若
,
,求异面直线
与
所成的夹角.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://img.xkw.com/dksih/QBM/2020/10/30/2582361868599296/2582829679149056/STEM/d8f69c07-c44e-4b6f-920b-38a2af2fb426.png?resizew=224)
(1)求证:四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aba63d391602d0798a1875da35fef40d.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c092ad8e71db52e8966993beebb50ee3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1826cf174638e4b20141069fa1f3c385.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
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解题方法
【推荐2】如图1,已知三棱锥
,图2是其平面展开图,四边形
为正方形,
和
均为正三角形,
,
分别为
,
的中点,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/2/650f264e-f75f-4f05-9ad1-f72e6e827293.png?resizew=488)
(1)求证:
;
(2)求二面角
的余弦值;
(3)若点
在棱
上,满足
,
,点
在棱
上,且
,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e742966e3711cfa53dce04022acf4bcc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6830ebecddbd9759be626289c408e4f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68b40d0d2f3cdd8981bb792ad87efb42.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/2/650f264e-f75f-4f05-9ad1-f72e6e827293.png?resizew=488)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7c545dcccb34fd8f83bfb23f2d1c23b.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74ec3d90e5f12cd8946d4dc638c1a357.png)
(3)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40f095541d8ac2d972743d3200f22e30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f297d79758d8803193db804f99b8909.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdba1337ec85fa9722cb4b320a82ae6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79498e1df1280868532f59ee8059a223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07b1e52dfd144ab4afda4d4aa5a92c1f.png)
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解答题-问答题
|
适中
(0.64)
【推荐1】如图所示,平面
平面
分别为
中点.
![](https://img.xkw.com/dksih/QBM/2016/8/11/1572973428137984/1572973434339328/STEM/990dd0d04768479e940e6b93fb8e42a5.png)
(1)证明:平面
平面
;
(2)若
,点
为棱
的三等分点(近
),平面
与平面
所成锐二面角的余弦值为
,求棱
的长度.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfa640b17a9d7bfb7242f27fe0a4012a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea6775f499217e01798fd7160f594ebf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1e7ac66ae7e429905d954f6978de023.png)
![](https://img.xkw.com/dksih/QBM/2016/8/11/1572973428137984/1572973434339328/STEM/990dd0d04768479e940e6b93fb8e42a5.png)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e954720d4c10dc05aad46e4e157ef74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fa7bbd7831e9ff4f8cffc8889d34f05.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/556c03caf910d3d5b604edb9d4fed455.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c5757f787d98f9a46777324b69ad672.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4e108d5c61e85e0741ec2c484fc5768.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
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解题方法
【推荐2】如图所示,在四棱锥
中,四边形ABED是正方形,点G,F分别是线段EC,BD的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/7/bd21d4b7-37e4-4e93-9883-fc5daf511d3a.png?resizew=128)
(1)求证:
平面ABC;
(2)若
平面ABC,且
,求异面直线GF与CD所成的角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1e038b4e76b3a368731d3331522b8e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/7/bd21d4b7-37e4-4e93-9883-fc5daf511d3a.png?resizew=128)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00b8c4ce6026a841c17f214dfba32285.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca5dd496ee0c1170ef6dcc48266ee444.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/846071242f981289741ad19f4e7190cf.png)
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