在如图所示的几何体中, △ABC为正三角形,AE和CD都垂直于平面ABC,且AE=AB=2,CD=1,F为BE的中点.
![](https://img.xkw.com/dksih/QBM/2016/1/20/1572450125946880/1572450131886080/STEM/467f32e39f61406390784910d6a56982.png)
(Ⅰ)求证:平面DBE⊥平面ABE;
(Ⅱ)求直线BD和平面ACDE所成角的余弦值.
![](https://img.xkw.com/dksih/QBM/2016/1/20/1572450125946880/1572450131886080/STEM/467f32e39f61406390784910d6a56982.png)
(Ⅰ)求证:平面DBE⊥平面ABE;
(Ⅱ)求直线BD和平面ACDE所成角的余弦值.
更新时间:2016-12-04 01:00:53
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解答题-问答题
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适中
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名校
【推荐2】如图所示,四边形ABCD为矩形,
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