如图,四边形
是直角梯形,
,
∥
,
,又
,直线
与直线
所成的角为
.
![](https://img.xkw.com/dksih/QBM/2011/6/3/1570236960415744/1570236965797888/STEM/a6e20f03341a4fd48aa1193516ccc884.png?resizew=289)
(1)求证:平面
平面
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e61ce105fc9653b120d6901b32780f03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8432a44f6c6b37f4961dc63521fa7f9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/892909e49156f7dcc0650fcd65243877.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47d71325da83869e15c37598926fc883.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0cb6273ffbe39ddedeec9dc95bcf556c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d50703c46b6153945d718b198f03b4b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be6a6301878fed2a01413020b27310a5.png)
![](https://img.xkw.com/dksih/QBM/2011/6/3/1570236960415744/1570236965797888/STEM/a6e20f03341a4fd48aa1193516ccc884.png?resizew=289)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d077f6da8b2c00b152d4679aa2ed7f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/324a1792318a3528772781fac2b4d2e4.png)
2011·山东潍坊·一模 查看更多[1]
(已下线)2011届山东省潍坊市三县高三最后一次模拟考试文数
更新时间:2016-11-30 21:58:11
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解答题-证明题
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【推荐1】如图,在三棱锥P ABC 中,PA平面ABC,PC AB,D,E分别为BC,AC的中点.求证:
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/21/e02e320f-4b6f-4f98-99a9-1145ec1bb214.png?resizew=185)
(1) AB / /平面PDE ;
(2)平面PAB平面PAC .
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/21/e02e320f-4b6f-4f98-99a9-1145ec1bb214.png?resizew=185)
(1) AB / /平面PDE ;
(2)平面PAB平面PAC .
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【推荐2】如图,三棱锥
中,平面
平面ACD,
,
,
,点
为棱AD的中点,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/14/9b78be7a-8a59-457f-8bb3-28b92723b7c0.png?resizew=176)
(1)求证:平面
平面BCD;
(2)求异面直线AB与CE所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3d7090639341730951c1bc3c9b6164e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3570a95f68349fcd9417fcda62e78e7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cfad1a2a4e9aa531fa1e127e3838b78.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/432cce1481829c4dfe2bd557f6e9aa4c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50f218914337edd06e59e75d90b777e6.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/14/9b78be7a-8a59-457f-8bb3-28b92723b7c0.png?resizew=176)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3d7090639341730951c1bc3c9b6164e.png)
(2)求异面直线AB与CE所成角的余弦值.
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【推荐1】如图所示,在三棱锥
中,
为等边三角形,
,
,点
在平面
内的射影恰好落在
上.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/17/cfc146de-23f6-40e8-b4d8-9c9516e2b093.png?resizew=163)
(1)求证:平面
平面
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63ab13ef156d034b710d811e09b0be34.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/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/17/cfc146de-23f6-40e8-b4d8-9c9516e2b093.png?resizew=163)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78a3fd5284e160896f07ce367645fd04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e820aec9c1a975242fe6d76408a9cde8.png)
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【推荐2】在四棱台
中,底面
是边长为2的菱形,
,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/13/0aa05c1d-dd0c-4ef0-96ec-7999a4ceebc5.png?resizew=218)
(1)证明:
平面
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d46f43920d092fa43fc2e588404d89c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3cf80b036459da6dcb841a4bbe3859fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/929b1726615353aff34060ba51964e45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12ac7bb94b8add76514638cb28ca3c45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92535536bd3c2761724fd058427f95a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ecfb8cf8b9dee47ff46500f4a3a8490.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/13/0aa05c1d-dd0c-4ef0-96ec-7999a4ceebc5.png?resizew=218)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a5928c98b341b16d4b5a5b931d2929d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc4fd5b13f66aaa25632811704596c44.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b0d903c63be7566fe2a5fa5bc0f221.png)
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【推荐3】如图,斜三棱柱
中,
为正三角形,
为棱
上的一点,
平面
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7f6f93171329d508d491143b9d71f7b.png)
平面
.
![](https://img.xkw.com/dksih/QBM/2022/4/14/2957990757892096/2959513984868352/STEM/d9619d37-a9f9-4c4b-a63e-143bd8ee8242.png?resizew=201)
(1)证明:
平面
;
(2)已知平面
平面
,求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4890e58791814622b87c4d60ea971f54.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7f6f93171329d508d491143b9d71f7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9bfa68259d7a331be323b2038d628a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7935fe3125f247b7bea4f065ce9ad985.png)
![](https://img.xkw.com/dksih/QBM/2022/4/14/2957990757892096/2959513984868352/STEM/d9619d37-a9f9-4c4b-a63e-143bd8ee8242.png?resizew=201)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a5928c98b341b16d4b5a5b931d2929d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9a8181f7a7fe7f3fac872ce9534f15.png)
(2)已知平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c50719bf366d8828e785620cb79e14a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0eb3edb9e444eb488f867bb22e57ab58.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45cbb74984939d59964559c3560ef7ba.png)
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