如图,在直三棱柱
中,
,点
为
上一点,且
平面
.
![](https://img.xkw.com/dksih/QBM/2023/5/31/3249535718957056/3298264834449408/STEM/65f896cbdcd64b16ac0456b61e035af4.png?resizew=160)
(1)求
的值;
(2)若三棱锥
的体积为
,求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e64cabc69fb1e437b50acdbf43e60306.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/896e293411e2fd0da215ff20781cb36a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f62fd0b510920be6bc60d170c3ff3da3.png)
![](https://img.xkw.com/dksih/QBM/2023/5/31/3249535718957056/3298264834449408/STEM/65f896cbdcd64b16ac0456b61e035af4.png?resizew=160)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b70ff4d92d1fbda025816f88e63478a.png)
(2)若三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98bb4f21d1699d81097b3934ebc2acb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37fbbc8f521edab89a7e373287bcfbd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f62fd0b510920be6bc60d170c3ff3da3.png)
更新时间:2023-08-08 08:39:53
|
相似题推荐
解答题-证明题
|
适中
(0.65)
名校
【推荐1】已知
,
都是
的边
的三等分点,
是
的中点,
,
,
,如图①.同时将
和
分别沿
,
折起,折起后
,如图②.
![](https://img.xkw.com/dksih/QBM/2021/4/30/2710837215027200/2711010888327168/STEM/a3de965a-e00f-48ad-a31d-0d9c0f5b68bf.png?resizew=463)
(1)在图②中,求证:
;
(2)在图②中,若
,求二面角
的余弦.
![](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/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d320f180419175d75eebc618cc458b39.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04725e51b4870658f74de79403e3898f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1682d306c38087d9e6f7efb9cec596a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/441dec590b47adc3678a291a3ec89a4a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55c3c8bf858c13b295de56e548116db9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccaee8f228ff24e7c89879bb5b999cf2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdab863f0a20477d3763e30dd5b432d.png)
![](https://img.xkw.com/dksih/QBM/2021/4/30/2710837215027200/2711010888327168/STEM/a3de965a-e00f-48ad-a31d-0d9c0f5b68bf.png?resizew=463)
(1)在图②中,求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d045abc40b9acb8d6d1f4d80cb4655e.png)
(2)在图②中,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16ed75e65e7374c38ffb1f75259a8beb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f1854ba6cc92481d7a616bd2788a47e.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
解题方法
【推荐2】如图,在等腰梯形ABCD中,
,
,将
沿着AC折到
的位置,使
.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/26/25629444-0165-429c-92ec-f10454fc7680.png?resizew=382)
(1)求证:平面
平面ABC;
(2)求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10df84d553a8826a7ce9bff4bf0d95b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852847ba02c2b62abf27e9cc11f596a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7ac5396c5ea442e0364b50c1db3d2da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9524e3810e06dc781285f1289e75d653.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfbad7ad1465d1c4c177e3321e6ed12a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/26/25629444-0165-429c-92ec-f10454fc7680.png?resizew=382)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1095b030f441de5fb223781b00f3dd9.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b33b7213d99a817bff19bcf740a0697c.png)
您最近一年使用:0次
解答题-问答题
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适中
(0.65)
【推荐3】如图,在四棱锥
中,侧棱
底面
,底面
为长方形,且
,
是
的中点,作
交
于点
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/14/2b8c847c-ce7a-4a76-b32c-f5c7803499aa.png?resizew=215)
(1)证明:
平面
;
(2)若三棱锥
的体积为
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5e84a62b385350e02a534046d6acf03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.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://img.xkw.com/dksih/QBM/editorImg/2023/1/14/2b8c847c-ce7a-4a76-b32c-f5c7803499aa.png?resizew=215)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c45fbffb9e2c7fa7c5006cde8da0cabe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
(2)若三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/398243832c62535aecf7a812e482afd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dac452fbb5ef6dd653e7fbbef639484.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a821b45899e2f07e99d315f583571c7.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】如图所示,四面体PABC中,E,F分别为AB,AC的中点,过EF作四面体的截面EFGH交PC于点G,交PB于点H,证明:
平面ABC
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4193fb98c610f41f9a6c89d046f13d32.png)
![](https://img.xkw.com/dksih/QBM/2021/8/1/2776929617936384/2821928735539200/STEM/615dd4092e354c68a51df8c4bead184d.png?resizew=301)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】如图,在四棱锥
中,平面
平面
,底面四边形
为直角梯形,
,
,
,
,
为线段
的中点,过
的平面与线段
,
分别交于点
,
.
![](https://img.xkw.com/dksih/QBM/2021/6/24/2750063488237568/2792390503153664/STEM/b05df7ba-8fc9-4e03-8089-c7ead61cef34.png?resizew=265)
(1)求证:
;
(2)若
为棱
上靠近
点的三等分点,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/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae1e04eeb4de72e5750dae77bcb6f88a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4795ee1f96b430529934e2231b38885d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e921f46d90e43f4517c55832b6280f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/931bbffda5e872703c9947eccc47ede2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://img.xkw.com/dksih/QBM/2021/6/24/2750063488237568/2792390503153664/STEM/b05df7ba-8fc9-4e03-8089-c7ead61cef34.png?resizew=265)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87a55b6148a783252baef627b4d9c59c.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5868de99a3e94b13316b0122f22d3f91.png)
您最近一年使用:0次
解答题-证明题
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适中
(0.65)
名校
【推荐1】在四棱锥
中,
平面
,
,
,
,
,点
,
在线段
上,满足
,
.
![](https://img.xkw.com/dksih/QBM/2021/8/15/2786470467837952/2792927882764288/STEM/0902d3d6-bb15-4047-819d-6aef37cd1bd3.png?resizew=232)
(1)求证:
;
(2)若
为线段
上的一点,且
平面
,求平面
与平面
所成锐二面角的余弦值.
![](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/f571396be1aa4a8914a66f7d7abd6381.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bd6a2b112facda441f4e34bf5c145fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3b10835116b9b777a666b438c907b49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0858af3c08375b4fbef381dbbf60277.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/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9f088f38b83513abad31278105833a3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5de9bdbe994c4cef2cd365a09686608.png)
![](https://img.xkw.com/dksih/QBM/2021/8/15/2786470467837952/2792927882764288/STEM/0902d3d6-bb15-4047-819d-6aef37cd1bd3.png?resizew=232)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd48dbf2728eeca9c014bedf166900d9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/826bf6fa3706921b77ad0eb4fcc206bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/642401af2d7fc2de640ff7f6a8715950.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/642401af2d7fc2de640ff7f6a8715950.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcfc4a37ea4887b18c25dcf26c821093.png)
您最近一年使用:0次
解答题-问答题
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适中
(0.65)
解题方法
【推荐2】在四棱锥
中,
,PD与平面
所成角的大小为
,点Q为线段
上一点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/18/fc58ac45-be3e-4b37-8365-4a17eb7ed4bb.png?resizew=146)
(1)若
平面
,求
的值;
(2)若四面体
的体积为
,求直线
与平面
所成角的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f59efe28601fca5840c9a0ceb04e645d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be6a6301878fed2a01413020b27310a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/18/fc58ac45-be3e-4b37-8365-4a17eb7ed4bb.png?resizew=146)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd4ed8a8a97fbc157434df36c3e361e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/450613b1e166a71f8c17c93f7dcbab97.png)
(2)若四面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7edc2e23df190c35aafad93410a05b8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18483c9c195ecd922772527fa85c0fcb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d7ffa7d57cb72ca3468f448e70b52af.png)
您最近一年使用:0次