如图四棱锥
的侧面
是正三角形,
面
,
且
,
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/5/f39b9bda-64ad-4842-8228-faa4f9971de4.png?resizew=164)
(1)求证:
面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)若
,求
与平面
所成角的正弦值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f9045e6cd575bbe76c89ef6ef852fd2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a5928c98b341b16d4b5a5b931d2929d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3aa5c57fd5dd7a19f18be1a819bb1f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4f654fde982fac75cc3f7a24a082c7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/5/f39b9bda-64ad-4842-8228-faa4f9971de4.png?resizew=164)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06222ee533c2484ab25321a6abbf98cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20bfdb2e89547af7a0ac0409a2a59cc7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/500df0e782bb081e608f4bc1d576afcf.png)
更新时间:2020-04-23 19:35:05
|
相似题推荐
解答题-证明题
|
适中
(0.65)
解题方法
【推荐1】如图,在长方体
中,
,
,点P为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/fb62fdd9-bfa1-4cf3-9aaa-b3baa880c7a2.png?resizew=160)
(1)求证:直线
平面PAC;(提示:可能需要作辅助线)
(2)求证:平面
平面
;
(3)分别叙述直线与平面平行的性质定理、平面与平面垂直的性质定理.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d262480ffb55b7617f44b63f130c154a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92535536bd3c2761724fd058427f95a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22adbc0da438220f9cace11b629d799b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/fb62fdd9-bfa1-4cf3-9aaa-b3baa880c7a2.png?resizew=160)
(1)求证:直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f11f1840eb8b17e7b07c3fe7e987a9c.png)
(2)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d077f6da8b2c00b152d4679aa2ed7f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc78a86b12ba0b4553135a3a635fc418.png)
(3)分别叙述直线与平面平行的性质定理、平面与平面垂直的性质定理.
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【推荐2】求证:如果一条线和两个相交平面都平行,那么这条直线和它们的交线平行.
您最近一年使用:0次
解答题-证明题
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名校
解题方法
【推荐1】如图,在几何体
中,四边形
是边长为
的菱形,且
,
,
,
,平面
平面
.
![](https://img.xkw.com/dksih/QBM/2021/4/29/2710485519810560/2710816896286720/STEM/4f4a837d-02af-4797-a69c-3853991ec28b.png?resizew=288)
(1)求证:平面
平面
;
(2)若平面
与平面
所成锐二面角的余弦值为
,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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6906f59d09ce31956d6f5ea2b23fc77.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/686171942bd7698035016c732db43b63.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d60513cfa8e0e96b436194834d738af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97ebdc05dbd46e98457b80c350538d02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79c1acdd27cebb11e0266464b03b3afb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/2021/4/29/2710485519810560/2710816896286720/STEM/4f4a837d-02af-4797-a69c-3853991ec28b.png?resizew=288)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd2d28f1e7a6b17401c19c34beddcbe0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b03428a8f91a5674cb8f54766c165f7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a09d9d486b7f91ba933210dd013a7f2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dee14db57f0c762aad845cf5b4a243c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
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【推荐2】如图,四棱柱ABCD﹣A1B1C1D1的底面ABCD为直角梯形,∠DAB=∠ADC=90°,AB=AD=1,CD=2,BD1⊥CD.点M为CD1的中点,且CD1=2BM.
(1)证明:平面BDM⊥平面BCD1;
(2)若钝二面角B﹣DM﹣C的余弦值为
,当BD1>BD时,求直线
与平面BCD夹角的余弦值.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/7/e881b15e-590a-409a-bfc4-703b8fb5bf28.png?resizew=192)
(1)证明:平面BDM⊥平面BCD1;
(2)若钝二面角B﹣DM﹣C的余弦值为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/021982f282a6cb554032f666c42a432d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/554b3b4c5ce7aca81becc07ed4903736.png)
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【推荐3】如图,在四棱锥P−中,底面ABCD为正方形,侧面ADP是正三角形,侧面ADP⊥底面ABCD,M是DP的中点.
(1)求证:AM⊥平面CDP;
(2)求直线BP与底面ABCD所成角的正弦值.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/20/d5e41997-9494-4029-b88f-fa7330b1a792.png?resizew=160)
(1)求证:AM⊥平面CDP;
(2)求直线BP与底面ABCD所成角的正弦值.
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