在三棱锥
中,平面
平面ABC,△
为等腰直角三角形,
,
,
,M为AB的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/16/fc928faa-91dd-4e87-bf13-c972e4170ec2.png?resizew=231)
(1)求证:
.
(2)求PC与平面PAB所成角的正弦值.
(3)在线段PB上是否存在点N,使得平面
平面PAB?若存在,求出
的值;若不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d077f6da8b2c00b152d4679aa2ed7f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/036de574712cad14bddadf6653c7e714.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/615fc8790237a1b09af51d6bcad6b595.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0028211551dd418eaaf51dde450f8b73.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/16/fc928faa-91dd-4e87-bf13-c972e4170ec2.png?resizew=231)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a7ebf74ae4daefad4350f9d1103a891.png)
(2)求PC与平面PAB所成角的正弦值.
(3)在线段PB上是否存在点N,使得平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e1b1b6da476086ecb79a3466b651097.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07b1e52dfd144ab4afda4d4aa5a92c1f.png)
更新时间:2021-11-11 10:11:20
|
相似题推荐
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】点E,F分别是正方形ABCD的边AB,BC的中点,点M在边AB上,且
,沿图1中的虚线DE,EF,FD将
,折起使A,B,C三点重合,重合后的点记为点P,如图2.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/23/a9c8b2d6-75ef-4db6-86d1-eab476fc067d.png?resizew=360)
(1)证明:
;
(2)若正方形ABCD的边长为6,求点M到平面DEF的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/75e17be2c43046cea9813d336f5b933f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c361a424dac89b427785be4a9c0c1fd.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/23/a9c8b2d6-75ef-4db6-86d1-eab476fc067d.png?resizew=360)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dac3b144cadc3c155f9bcc54766364a5.png)
(2)若正方形ABCD的边长为6,求点M到平面DEF的距离.
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解题方法
【推荐2】如图,在正方体
中,
,
为上底面
的中心.
;
(2)求点
到平面
的距离;
(3)判断棱
上是否存在一点
,使得
?并说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92535536bd3c2761724fd058427f95a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632f2bf1cd0435041fa04b01901d1c8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07d6b98ecb4793c9f063f1f6b61caa19.png)
(2)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7935fe3125f247b7bea4f065ce9ad985.png)
(3)判断棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b18c0b2b38a140896f65eb3d3f942c1.png)
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解答题-证明题
|
适中
(0.65)
解题方法
【推荐1】如图已知正四棱柱ABCD----A1B1C1D1,AB=1,AA1=2,点E为CC1的中点,点F为BD1的中点.
![](https://img.xkw.com/dksih/QBM/2011/12/26/1570633508806656/1570633514221568/STEM/9fbb3d4f699042d6a6d5aba2e8e52709.png?resizew=249)
(1)证明:
平面
;
(2)求点
到平面BDE的距离;
(3)求
与平面BDE所成的角的余弦值.
![](https://img.xkw.com/dksih/QBM/2011/12/26/1570633508806656/1570633514221568/STEM/9fbb3d4f699042d6a6d5aba2e8e52709.png?resizew=249)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a5f445af1ae136773cb338920552ff2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02458d967ac5d2bbf8a27f7369aa76fa.png)
(2)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
(3)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fe734023d4e70010a6b2cc3267cb86e.png)
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解答题-问答题
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【推荐2】如图,在四棱锥
中,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/7/a7e6a804-de17-4382-894f-0fef915a6d66.png?resizew=179)
(Ⅰ)证明:
;
(Ⅱ)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/e9c44606677ace91e726a26c11d99d1d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/182cbd109fa84a4606a12e9120e9c5b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56e5a8fdbfbdf25f6937b7a2d6a4cd95.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/7/a7e6a804-de17-4382-894f-0fef915a6d66.png?resizew=179)
(Ⅰ)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e5ea309886e947ea7cb4b81716206fd.png)
(Ⅱ)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
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名校
【推荐1】如图,四棱锥
底面
是矩形,
面
,
,
、
是棱
、
上的点,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/24/b72cf942-135d-4617-b1c3-9428b935547e.png?resizew=118)
(Ⅰ)求证:
平面
;
(Ⅱ)棱
上是否存在点
,使
面
?若存在,求出
的值;不存在,请说明理由.
![](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/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e50c329f1f58ee819e67ee6ccba0636.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/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f2c0cb5e5bb9636c1de7ca151b8fb17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48a785133f7de9c48fcfa24a6d838eed.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/24/b72cf942-135d-4617-b1c3-9428b935547e.png?resizew=118)
(Ⅰ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dcafa398cc6b6079883e7ad153eb62d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
(Ⅱ)棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34cf61780928291d51c7bbb08a5fcf81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/037f00f51c64d7dde2d46517003bca65.png)
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【推荐2】已知边长为6的等边三角形△ABC中,点M,N分别是边AB,AC的三等分点,且
,
,沿MN将△AMN折起到
的位置,使
.
![](https://img.xkw.com/dksih/QBM/2022/3/21/2941121882218496/2942523532910592/STEM/b3683318-1871-4986-a350-d18c8fce2863.png?resizew=304)
(1)求证:
平面MBCN;
(2)在线段BC上是否存在点D,使直线
与平面
所成角为60°?若存在,求BD;若不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba486b7a12ec874644dc5fea93a56916.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3a45b6f1348711bc6eabd87982c3756.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8e7040c2fd8a163d71e35805775feb8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55d938067915b0d59f491b4c8ee7a982.png)
![](https://img.xkw.com/dksih/QBM/2022/3/21/2941121882218496/2942523532910592/STEM/b3683318-1871-4986-a350-d18c8fce2863.png?resizew=304)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8eedf1e774ce129d9a09f02ca1920052.png)
(2)在线段BC上是否存在点D,使直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a21897349d3d7c94419692106887153.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34c932cfbb9fb63159a176a8f45489a5.png)
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