如图所示,在四棱锥
中,
底面
,
,
,
,
,
,
,
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/4/9d7ce8fa-3fa1-4582-9502-f9548a45e6bd.png?resizew=180)
(1)求证:
平面
;
(2)求直线
与平面
所成角的正弦值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b80ee363635d73f601654339028daec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45acdbac251ca6b76a166c1242e71df9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68b40d0d2f3cdd8981bb792ad87efb42.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa7aeb2a8d1437eeb4482c3b6ad9f315.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d4746df85049d1651d3f6c30212a7a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa18c2a78c400c80a5760743f31771c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/4/9d7ce8fa-3fa1-4582-9502-f9548a45e6bd.png?resizew=180)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/321302db9ce1bf9ef167c0d3831d5154.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e6c2dad46a9052a4185a4f7b4ae8a2e.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
更新时间:2019-10-23 16:44:39
|
相似题推荐
解答题-问答题
|
适中
(0.65)
名校
【推荐1】如图,在棱柱
中,
为棱
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/28/811272aa-48cf-48f1-a24b-7a13651554ef.png?resizew=124)
(1)证明:
平面
;
(2)若该三棱柱为正三棱柱,且所有棱长均相等,求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/289d7a880379d6060065c829b45b0ed6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/28/811272aa-48cf-48f1-a24b-7a13651554ef.png?resizew=124)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf36e6d587a2c3dbb344c98a0090f03d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41104641f3e2260d00aeadf8fb8a078a.png)
(2)若该三棱柱为正三棱柱,且所有棱长均相等,求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41104641f3e2260d00aeadf8fb8a078a.png)
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解答题-证明题
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解题方法
【推荐2】如图,在四棱锥中,底面ABCD是正方形,侧面
底面ABCD,E,F分别为PA,BD中点,
.
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57f9d682e5d3cc8573574d8d11636758.png)
(2)在棱PC上是否存在一点G,使
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36148e5b0d89ba45bd98b91da00bf2b5.png)
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【推荐1】已知四面体ABCD的顶点坐标分别为
,
,
,
.
(1)若M是BD的中点,求直线CM与平面ACD所成的角的正弦值;
(2)若P,A,C,D四点共面,且BP⊥平面ACD,求点P的坐标.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a2d977eaaf129783581dcee97f44c96.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e2755d7f7751444a6ee6de623bdd836.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4886655e4272d2a5eb40adf508e4aa6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4ecacd53b31c86a5bd5e49e98badac0.png)
(1)若M是BD的中点,求直线CM与平面ACD所成的角的正弦值;
(2)若P,A,C,D四点共面,且BP⊥平面ACD,求点P的坐标.
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【推荐2】如图,在三棱柱
中,△ABC是边长为2的正三角形,顶点
在底面ABC的投影为AB的中点O,已知
与底面ABC内所有直线所成角中的最小值为
,M为棱
上一点.
![](https://img.xkw.com/dksih/QBM/2022/5/6/2973399710457856/2974485636784128/STEM/cd770189-fc68-4cbf-baf2-24590861df11.png?resizew=249)
(1)求三棱锥
的体积;
(2)若
,求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af9955b5aebb73cd84447e8541f901ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://img.xkw.com/dksih/QBM/2022/5/6/2973399710457856/2974485636784128/STEM/cd770189-fc68-4cbf-baf2-24590861df11.png?resizew=249)
(1)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c868ec5de0af022feee3eeb98e2c30ae.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d303f299e07c5eb5eefc7a80e574c65e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/800faf43a424f2dd708d1426e4e91615.png)
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