如图,四棱锥
的底面是正方形,
底面
,
,E是棱PB的中点.
(1)证明:直线
平面PBC;
(2)求直线DE与平面PAD所成角的余弦值.
![](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/de2479cd9055e57e504d64ea7d97e71e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/21/0b5e7e9c-31ec-4bf1-9857-b35a8cdf1d8d.png?resizew=203)
(1)证明:直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f4c3f9dd5d0343597a7f58a1989b537.png)
(2)求直线DE与平面PAD所成角的余弦值.
更新时间:2023-07-18 09:55:22
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相似题推荐
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐1】如图,在四棱锥
中,
底面ABCD,
,
,
,PA=AB=BC,E是PC的中点.求证:
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/28/4d07cfb4-486f-4606-802c-bb4baaa264dd.png?resizew=160)
(1)
;
(2)
平面ABE.
![](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/1134c8e3440abb6cd385af2c169037fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3bf10d92f20501e19d25f6f4159aab89.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05740f0c6071846227dc0ec177ad15e8.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/28/4d07cfb4-486f-4606-802c-bb4baaa264dd.png?resizew=160)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7dac702fe64edf1bc265da4b98cf2a0.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a1b49f64e0065edad868b25e9fcada3.png)
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解答题-证明题
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解题方法
【推荐2】如图,已知四棱锥
中,底面
是直角梯形,
,
,
,
,
平面
,
.
![](https://img.xkw.com/dksih/QBM/2011/2/19/1570002572820480/1570002577965056/STEM/d09771798a7a4ecba9ba74897b2f4f47.png?resizew=228)
(1)求证:
平面
;
(2)求证:
平面
;
(3)若M是PC的中点,求三棱锥M—ACD的体积.
![](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/68d31600cba2d5256c7e78b6122d6755.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1602c3d3e9628cd503a443024410e87a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8e2a44d05b1d387150c4b359e021ffc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.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/fcc532cfe64300cb3da9e04a307c957a.png)
![](https://img.xkw.com/dksih/QBM/2011/2/19/1570002572820480/1570002577965056/STEM/d09771798a7a4ecba9ba74897b2f4f47.png?resizew=228)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/307807ee10071bafbe922eb18d2517d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ffc6952e988d04f22f0fb2f7f0ab7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
(3)若M是PC的中点,求三棱锥M—ACD的体积.
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解答题-证明题
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适中
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名校
【推荐1】如图,在四棱锥P-ABCD中,
平面ABCD,底面是棱长为1的菱形,
,
,M是PB的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/6/ff703af4-7384-4993-9c61-d2b7031a5ebc.png?resizew=139)
(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/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a58a622e2b1a239f2f96aa1501e9799.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/364d6c88726d8c3bb8ed297057332bac.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/6/ff703af4-7384-4993-9c61-d2b7031a5ebc.png?resizew=139)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36222db36e348661eb5f616820e4e60f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af68a7bf0da4f7c6f739d2e2461ad9b7.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db54223bb3fc2fe2497213a4d1f94827.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
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解答题-证明题
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适中
(0.65)
【推荐2】如图(1).在
中,
,
,
,
、
分别是
、
上的点,且
,将
沿
折起到
的位置,使
,如图(2).
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/17/08f9eacc-03f7-495b-8cb6-f16985a35f7d.png?resizew=298)
(1)求证:
平面
;
(2)当点
在何处时,三棱锥
体积最大,并求出最大值;
(3)当三棱锥
体积最大时,求
与平面
所成角的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87fd28b8b2bde9de5630a6106a6f762e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e3262fc038bbec5e7c8cc47df08bef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f8eeeea1c9652cacce976f8129cf520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1682d306c38087d9e6f7efb9cec596a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f82957366f4c9272b6ee99126d4b6bf2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f460edcced5597615113c0fdc95b1dfc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f07107087ce4abdfa5fc68fe6fb62f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fffbf41f3890efb6956907ad3c4062a0.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/17/08f9eacc-03f7-495b-8cb6-f16985a35f7d.png?resizew=298)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ffc6952e988d04f22f0fb2f7f0ab7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a148a5584e41408fc74f8bd386b5b8.png)
(2)当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db4c18aba9681a8475968248764d4c3a.png)
(3)当三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db4c18aba9681a8475968248764d4c3a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9afac7c616bbb14e1ed428a3c507c7dc.png)
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解答题-问答题
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(0.65)
名校
【推荐3】如图,在四棱锥
中,
,
,
,
,
,
,
.
平面
;
(2)求
与平面
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87830eb5bc4f4f02e706b1557173a2d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f571396be1aa4a8914a66f7d7abd6381.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080db3af81b29ed10144a1c2e2a4fb8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c2753753faf2cb9a0003aa8e3945159.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa7aeb2a8d1437eeb4482c3b6ad9f315.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68b40d0d2f3cdd8981bb792ad87efb42.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4836945f324c29ef818b423bcc017a93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/689c065652544780be8b33ae92cbb6d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
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