如图,三棱的柱,
中,
平面
,
,点
在线段
上,且
.
![](https://img.xkw.com/dksih/QBM/2016/5/30/1572653876027392/1572653882204160/STEM/d1110d51ed5540d2b19ee9f25ac97448.png)
(1)求证:直线
与平面
不平行;
(2)设平面
与平面
所成的锐二面角为
,若
,求
的长;
(3)在(1)的条件下,设平面
平面
,求直线
与
所成的角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57f47d6a88e962cd790d2f159c021ec1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19434b67703318b18be7efee7be590bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd4f0e00fa66a406e2b1e74fe93da57a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ce7728a21d95c2e67918899131632b0.png)
![](https://img.xkw.com/dksih/QBM/2016/5/30/1572653876027392/1572653882204160/STEM/d1110d51ed5540d2b19ee9f25ac97448.png)
(1)求证:直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)设平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ba9e20d667d04bf3ee7f55cc795ce01.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/26ab55147ca5c0f958af43b0637ee31b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45ce6a5f580bdd91e3eb4771ba843fa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
(3)在(1)的条件下,设平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a819c3421d087bd3eb2504b59812d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ddd6f80993ce27b2619335e0d83bec57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
更新时间:2016-12-01 22:02:40
|
相似题推荐
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】在如图的空间几何体中,四边形BCED为直角梯形,∠DBC=90°,BC=2DE,AB=AC=2,CE=AE=
,且平面BCED⊥平面ABC,F为棱AB中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/2/4ecbc9c9-69d4-4259-85b2-6badf344032e.png?resizew=201)
(1)证明:DF⊥AC;
(2)求二面角B﹣AD﹣E的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7ffe8515ff6183c1c7775dc6f94bdb8.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/2/4ecbc9c9-69d4-4259-85b2-6badf344032e.png?resizew=201)
(1)证明:DF⊥AC;
(2)求二面角B﹣AD﹣E的正弦值.
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适中
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名校
【推荐2】如图,在直三棱柱
中,
,
,
分别是
,
的中点.
![](https://img.xkw.com/dksih/QBM/2017/2/4/1619478440148992/1619478440525824/STEM/2056a0789fce4f738c2e1646cef7a4bb.png)
(1)求证:
∥平面
;
(2)求证:平面
平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d900531973c546625694146fa1509ab9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://img.xkw.com/dksih/QBM/2017/2/4/1619478440148992/1619478440525824/STEM/2056a0789fce4f738c2e1646cef7a4bb.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56f7ba05c54b3de1f4378f7c8eb58328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/657dffbd3623b705f871878fbd9df57e.png)
(2)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7b3e7c7845a0ec3cbac709fda131764.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9a8181f7a7fe7f3fac872ce9534f15.png)
您最近一年使用:0次
解答题-证明题
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适中
(0.65)
名校
解题方法
【推荐1】如图,在三棱柱
中,侧棱
平面
,
,点D是
的中点.
![](https://img.xkw.com/dksih/QBM/2022/5/10/2976615723720704/2978395040153600/STEM/ee631d5c-332d-4622-858d-1f32b60f42e3.png?resizew=198)
(1)求证:
;
(2)求证:
平面
;
(3)求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5845ccc0d735dc14c92a8926d9b1def6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c64126356d8b6793eb92989664647f3a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/2022/5/10/2976615723720704/2978395040153600/STEM/ee631d5c-332d-4622-858d-1f32b60f42e3.png?resizew=198)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/429228f882da65a8e0064c88d02b8e40.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02cb62f4c1e0e023619922eb8a509c98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbc7e774e4ae40c23bf4ceed179230ca.png)
(3)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/078b7affe55314f956b8b105fe42a2d7.png)
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解答题-证明题
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适中
(0.64)
【推荐2】如图1,等腰梯形
中,![](https://img.xkw.com/dksih/QBM/2016/1/4/1572413787348992/1572413792845824/STEM/9469d0fd1af34d20bb3c3a3e3336236f.png)
是
的中点,如图2将
沿
折起,使面
面
连接
是棱
上的动点.
![](https://img.xkw.com/dksih/QBM/2016/1/4/1572413787348992/1572413792845824/STEM/313ab4c6378d4190931704cf9963d4da.png)
(1)求证:![](https://img.xkw.com/dksih/QBM/2016/1/4/1572413787348992/1572413792845824/STEM/dd915c5c5d9746fc9c49acd75f737e7d.png)
(2)若
当
为何值时,二面角
的大小为
![](https://img.xkw.com/dksih/QBM/2016/1/4/1572413787348992/1572413792845824/STEM/38daf861e67e4bafb21345a9e1e7c0dd.png)
![](https://img.xkw.com/dksih/QBM/2016/1/4/1572413787348992/1572413792845824/STEM/9469d0fd1af34d20bb3c3a3e3336236f.png)
![](https://img.xkw.com/dksih/QBM/2016/1/4/1572413787348992/1572413792845824/STEM/ef8b506995e54d168cca39007849bb3e.png)
![](https://img.xkw.com/dksih/QBM/2016/1/4/1572413787348992/1572413792845824/STEM/236c6a0d035846da967e23cea8dd8779.png)
![](https://img.xkw.com/dksih/QBM/2016/1/4/1572413787348992/1572413792845824/STEM/4db58ca4699f4801ab14a611a3f57828.png)
![](https://img.xkw.com/dksih/QBM/2016/1/4/1572413787348992/1572413792845824/STEM/064a2473628b496a9601cecdbe8b128a.png)
![](https://img.xkw.com/dksih/QBM/2016/1/4/1572413787348992/1572413792845824/STEM/6d0930600cea4b508e2db721c7894078.png)
![](https://img.xkw.com/dksih/QBM/2016/1/4/1572413787348992/1572413792845824/STEM/ddf0aaedb17a49e482981fcbc60d25e4.png)
![](https://img.xkw.com/dksih/QBM/2016/1/4/1572413787348992/1572413792845824/STEM/c1602dbaeb664a1baef9642d0f679aa0.png)
![](https://img.xkw.com/dksih/QBM/2016/1/4/1572413787348992/1572413792845824/STEM/236c6a0d035846da967e23cea8dd8779.png)
![](https://img.xkw.com/dksih/QBM/2016/1/4/1572413787348992/1572413792845824/STEM/313ab4c6378d4190931704cf9963d4da.png)
(1)求证:
![](https://img.xkw.com/dksih/QBM/2016/1/4/1572413787348992/1572413792845824/STEM/dd915c5c5d9746fc9c49acd75f737e7d.png)
(2)若
![](https://img.xkw.com/dksih/QBM/2016/1/4/1572413787348992/1572413792845824/STEM/409dfbb43f73448d9d22dd6ff87bb5f4.png)
![](https://img.xkw.com/dksih/QBM/2016/1/4/1572413787348992/1572413792845824/STEM/fb1a1552be844de6b2b0ca587345946e.png)
![](https://img.xkw.com/dksih/QBM/2016/1/4/1572413787348992/1572413792845824/STEM/d0e1646090424fa0b5a7ba69000fdfb2.png)
![](https://img.xkw.com/dksih/QBM/2016/1/4/1572413787348992/1572413792845824/STEM/5971f49a319b4eb4b2cff252016a79a3.png)
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