如图,三棱锥
中,所有棱长均为6,
,
分别是
,
的中点,
在
上,
在
上,且有
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/22/ff096fe6-3283-4f18-9e83-7b8bb148467f.png?resizew=178)
(1)证明:直线
,
,
相交于一点;
(2)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bba4af8c208559d62dcf2ddfb4e1d19.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/22/ff096fe6-3283-4f18-9e83-7b8bb148467f.png?resizew=178)
(1)证明:直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e42887d9bf31c1dd99f13c39e63c9ab9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c63e36329f5e0979f5ee776ac5d06327.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
更新时间:2023-12-22 14:58:59
|
相似题推荐
解答题-证明题
|
适中
(0.65)
解题方法
【推荐1】如图,在正四棱柱
中,
,
,E为
的中点,经过BE的截面与棱
,
分别交于点F,G,直线BG与EF不平行.
共点;
(2)当
时,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e55a2310cbba5e050488cd9296eb195d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/394c5d2f55221975503be8aa18022480.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22adbc0da438220f9cace11b629d799b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25cfd898d33c71be3c212277d9e4da2a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0acbd5d35287047b8ff024d00a3eaec0.png)
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名校
解题方法
【推荐2】如图,已知平面
,且
,设在梯形
中,
,且
.求证:
共点.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4e288596fa3811dd2c17bded60e82e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40b707f5ee4fbb2e637c65fbc6d8ed03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/132078d5f2e4e80b10879952cecc3465.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a443d4b3b4691f75b13cb52aaf3ee654.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fda44a1a3d6d50627261fcee68d0d07a.png)
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解答题-问答题
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适中
(0.65)
名校
解题方法
【推荐1】如图,在四棱锥
中,
底面
,
,
,
,点E为棱
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/31/4fb39a38-e3ed-4fee-a6ac-cdf3004b6bf0.png?resizew=168)
(1)证明:平面
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/ee8ef58be8708144272538ee427fb92c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3fb3e724d5ebb26d9f4ffa41ab8c9ce4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33e4f924fb8fda8fd662eec5613623b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/31/4fb39a38-e3ed-4fee-a6ac-cdf3004b6bf0.png?resizew=168)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78a3fd5284e160896f07ce367645fd04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
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【推荐2】在四棱锥P−ABCD中,已知侧⾯PCD为正三角形,底⾯ABCD为直角梯形,AB//CD,∠ADC=
,AB=AD=3,CD=4,点M,N分别在线段AB,PD上,且
=2.
(1)求证:PM//平⾯ACN;
(2)若点P到平⾯ABCD的距离为
,求直线AC和平⾯PAB所成角交的正弦 值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6380f35cdd3050759a4a91b8637adc1e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca68c83551df910b16484212bcdf1d01.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/28/d0382689-cdb0-450c-a213-a55e38120a53.png?resizew=199)
(1)求证:PM//平⾯ACN;
(2)若点P到平⾯ABCD的距离为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95bacae35b6e16a0a33c2bdc6bc07df7.png)
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