如图,斜三棱柱
中,侧面
与侧面
都是菱形,
,
.
(Ⅰ)求证:
;
(Ⅱ)若
,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/2d9a8181f7a7fe7f3fac872ce9534f15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2537248187ed26219ed39e5fa2a51eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bb5b12692517a39c320f99a479eb055.png)
(Ⅰ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3eabb853db0d2226af9cb2f1722a4ab4.png)
(Ⅱ)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ff55ee86c442c784d98be7285e046ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56f7ba05c54b3de1f4378f7c8eb58328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b94e97d085cea077cb82a0b7d2f523e.png)
![](https://img.xkw.com/dksih/QBM/2017/7/8/1732911359795200/1790266705248256/STEM/cc45ea10acce43c582e69d744746db0b.png?resizew=223)
更新时间:2016-12-04 17:22:30
|
相似题推荐
解答题-证明题
|
适中
(0.65)
【推荐1】如图1所示,等边
的边长为
,
是
边上的高,
,
分别是
,
边的中点.现将
沿
折叠,如图2所示.
(1)证明:
;
(2)折叠后若
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/878e89b6eca35e34c863e832a2c661db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/31/c76eca36-28ef-4e17-a0f6-12c20f1d0d9f.png?resizew=333)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/316c97c5b6f7c0fbdf7b9e4b9fccb661.png)
(2)折叠后若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d42e97eee705d164e6ac6de9ecd6d1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55ab246caa47712901bff6788ca4a455.png)
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解答题-证明题
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适中
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名校
【推荐2】如图,在四棱锥
中,底面
为直角梯形,
,
,
底面
,且
,
、
分别为
,
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/22/91160166-f48a-4fa2-8813-f5657a4175ff.png?resizew=179)
(1)求证:
;
(2)求
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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34e0a957a55460c72673c0f2ee90dbb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce0d7095ddd69d6ceaf1065b1bc2c79d.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/0ae172ead4020c20f9618b4f540e8044.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/22/91160166-f48a-4fa2-8813-f5657a4175ff.png?resizew=179)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/962515007ca98ad2d36557b60a42ad6f.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a406f24b5131eb7da9127750319e52.png)
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解答题-证明题
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【推荐3】如图,直角梯形ABCD与等腰直角三角形ABP所在的平面互相垂直,且
,
,
,
,
.
(1)求证:
;
(2)求直线PC与平面ABP所成角的余弦值;
(3)线段PA上是否存在点E,使得
平面EBD?若存在,求出
的值;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f79863ffcfa63117ca6741b20a48e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080db3af81b29ed10144a1c2e2a4fb8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f92d681685fecaa72dcf38eda81852c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e921f46d90e43f4517c55832b6280f9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/26/b8953804-4721-4650-a679-bc8fcb129956.png?resizew=156)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c583493109d50c9e4634c05e9042a9f.png)
(2)求直线PC与平面ABP所成角的余弦值;
(3)线段PA上是否存在点E,使得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6bb178784aa857d4d4683e650273f054.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7035d954e76a15924de818e7e10e924a.png)
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解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】如图,已知正三棱柱
中,所有棱长均为2,点E,F分别为棱
,
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/12/2db17816-73a6-4e3e-91ad-8224a1c714a3.png?resizew=149)
(1)求
与平面AEF所成角的正弦值;
(2)过A、E、F三点作一个平面,则平面AEF与平面
有且只有一条公共直线:
①这一结论可以通过空间中关于平面的一条基本事实(也称为公理)得出,请写出该基本事实的内容;
②求这条公共直线在正三棱柱底面
内部的线段长度.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/12/2db17816-73a6-4e3e-91ad-8224a1c714a3.png?resizew=149)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ce1b066f8869d0ff4513f7a99745125.png)
(2)过A、E、F三点作一个平面,则平面AEF与平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99b16cff607cdc2d69afc70dc778acbb.png)
①这一结论可以通过空间中关于平面的一条基本事实(也称为公理)得出,请写出该基本事实的内容;
②求这条公共直线在正三棱柱底面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99b16cff607cdc2d69afc70dc778acbb.png)
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解答题-证明题
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适中
(0.65)
【推荐2】如图,在三棱锥
中,侧棱
底面
,且
,
,过棱
的中点
,作
交
于点
,连接
,
.
(1)证明:
;
(2)若
,三棱锥
的体积是
,求直线
与平面
所成角的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/587df01a98f499a9f361aafd8c3dac39.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/615fc8790237a1b09af51d6bcad6b595.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a4a6a1e70241d600bc6c104313eac61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/4/e75dd94d-92fc-4b7f-a681-7a0a8e1e8a7e.png?resizew=131)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aaef9e92d148afff22761d5e027d3ee.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b80ee363635d73f601654339028daec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b115316e0fcd2ef46a4dd383472996e4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0467b0675c3ecfb282cc88255284d3e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b03428a8f91a5674cb8f54766c165f7e.png)
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解答题-证明题
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适中
(0.65)
名校
【推荐3】如图,在三棱锥P-ABC中PA⊥平面ABC,AC⊥BC,D为PC中点,E为AD中点,PA=AC=2,BC=1.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/26/f14a2ea9-9f30-4a82-94ec-96fd81d87ed1.png?resizew=143)
(1)求证:AD⊥平面PBC;
(2)求PE与平面ABD所成角的正弦值;
(3)设点F在线段PB上,且
,EF∥平面ABC,求实数
的值.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/26/f14a2ea9-9f30-4a82-94ec-96fd81d87ed1.png?resizew=143)
(1)求证:AD⊥平面PBC;
(2)求PE与平面ABD所成角的正弦值;
(3)设点F在线段PB上,且
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c73c3fb76b36c10659f53b68147ba250.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
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