如图,在三棱柱
中,底面三角形
是边长为4的正三角形,侧面
是菱形,且平面
平面
分别是棱
的中点,
.![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
平面
;
(2)若①三棱锥
的体积为8;②
与底面
所成角为
;③异面直线
与
所成的角的大小为
.请选择一个条件求平面
与平面
所成角(锐角)的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9a8181f7a7fe7f3fac872ce9534f15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61cdaadeae37736a1e6dd93fa1fe712f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b12fa54e80fc52de0701cddc9a4ed47e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61ea285e96bf2e3b6406151bb694f10a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59a6ae5630f5b5be2bbdd8ef05c0baad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
(2)若①三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/861d61d2b7b16e12fd97f870fb3fa522.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53e97fcdcfd6183b976a61ef3222c607.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d5bca00fa20e6e80480b9d06d2e52ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1859959fdb4c5edd8056893f94a10a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ac09dc1ca2cdd7aef28c218763d3e4d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ffe8a84ca3a13f82aff1a022edc66065.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
更新时间:2023-10-11 21:08:24
|
相似题推荐
解答题-证明题
|
适中
(0.65)
【推荐1】如图,在三棱台
中,平面
平面
,
,
,
,
,点
是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/14/15163710-6784-4f61-91d6-0fc76a1cb0ee.png?resizew=176)
(Ⅰ)求证:
平面
;
(Ⅱ)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/0671b4776e142e17a79af5b3f0378ef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af260e0d98c95d1e092dc4c6d348e3ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8ffcb17afd083b37c0946e9bea9bcfa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8a7b5adfcac0f46a4cd19da4ebb4a2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef0402dd5ae3db10281f9f1e11738bcb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/14/15163710-6784-4f61-91d6-0fc76a1cb0ee.png?resizew=176)
(Ⅰ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d3d8696563b1a71c62b449c90c1253f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
(Ⅱ)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.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2】如图,在四棱锥
中,底面
是边长为2的菱形,
是
的中点,
分别是棱
上靠近点
和点
的三等分点,
.
![](https://img.xkw.com/dksih/QBM/2022/7/1/3013104712400896/3013956856807424/STEM/93de8c677fef4e0aa6515cc6ab7c6fae.png?resizew=255)
(1)证明:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d9b798a71ae94839e1ebb0a644202e8.png)
平面
.
(2)求点
到平面
的距离.
![](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/6b6e20c4731895d251346b493c70231c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a18acf6f3ac34f1ed86416d83ae4ee7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4f1797c520252319dcc0195b720aec6.png)
![](https://img.xkw.com/dksih/QBM/2022/7/1/3013104712400896/3013956856807424/STEM/93de8c677fef4e0aa6515cc6ab7c6fae.png?resizew=255)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d9b798a71ae94839e1ebb0a644202e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
(2)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
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解答题-证明题
|
适中
(0.65)
名校
【推荐1】如图所示,四棱锥P﹣ABCD中,平面PAD⊥平面ABCD,PA=PD
,四边形ABCD为等腰梯形,BC∥AD,BC=CD
AD=1,E为PA的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/30/4b39f0d5-0dbe-4eb4-810f-70a80e8cc72a.png?resizew=174)
(1)求证:EB∥平面PCD;
(2)求平面PAC与平面PCD所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/074609663cc1cfa6cf35a2ae9bfc1164.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52c70c0c5a061195b9941796b6a9acc4.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/30/4b39f0d5-0dbe-4eb4-810f-70a80e8cc72a.png?resizew=174)
(1)求证:EB∥平面PCD;
(2)求平面PAC与平面PCD所成角的余弦值.
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
【推荐2】如图,在三棱锥P-ABC中,△ABC为等边三角形,PA=AB=2,PB=PC=2
.
![](https://img.xkw.com/dksih/QBM/2021/9/16/2809487997706240/2815193386582016/STEM/73592926-6c71-44a6-837d-56cd7b12c957.png?resizew=275)
(1)证明:BC⊥PA.
(2)若
,求二面角B-AQ-C的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://img.xkw.com/dksih/QBM/2021/9/16/2809487997706240/2815193386582016/STEM/73592926-6c71-44a6-837d-56cd7b12c957.png?resizew=275)
(1)证明:BC⊥PA.
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa3aab4d2fdb58b196eb17e94c08bd15.png)
您最近一年使用:0次