如图,在三棱台
中,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/10/bc81f980-bf17-4ba0-b0c5-ec1d00603f6e.png?resizew=191)
(1)求证:平面
平面
;
(2)若四面体
的体积为2,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/986ba572d8373df48c996f8c8611498c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acd254b91edb60599779e737c2bd87e9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/10/bc81f980-bf17-4ba0-b0c5-ec1d00603f6e.png?resizew=191)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5352d28609d1b3d09a0a29d023d1bb72.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)若四面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1cf2fa3cb87267ee5f968c2a9362d216.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/147310251a463539f66374c1f452fb67.png)
2023·浙江嘉兴·二模 查看更多[5]
浙江省嘉兴市2023届高三下学期4月教学测试(二模)数学试题山东省安丘市青云学府2023届高三二模考前适应性练习(二)数学试题(已下线)数学(云南,安徽,黑龙江,山西,吉林五省新高考专用)(已下线)专题05 立体几何(已下线)押新高考第20题 立体几何
更新时间:2023-04-09 07:50:13
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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】在正三棱柱
中,点
是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/12/90ac46e4-a6d2-4335-bd1e-e9a7a90e085d.png?resizew=155)
(1)求证:
//面
;
(2)设
是棱
上的点,且满足
.求证:面
面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/12/90ac46e4-a6d2-4335-bd1e-e9a7a90e085d.png?resizew=155)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ee8456443402a25b1e25d35ff7e1c98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5888bec948373f3854258ad80171073d.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ed990271713e2d0ee431ce152f0b6d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0fe22d526d1da4d61436c59e7517328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3653ada76ba0c8afe9d57c8e7832c6ed.png)
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【推荐2】如图,在四棱锥
中,底面
为矩形,平面
平面
,
,
,
为
的中点..
(1)求证:平面
平面
;
(2)
,在线段
上是否存在一点
,使得二面角
的余弦值为
.请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80c753cb1eb73fd8d136d00462970797.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cf9a6db3571fa57bfa2d5e4d44c51b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c09afc70f448545336304333d5b5658b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a4d24165efcd72b9bc8698152a73a72.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df1ac3ab8d3ce5e61fd2f89761f80976.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15f3e3f310f6ec3f3a26498e7ee17a00.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c66d99a6a8415ddad22bbed33b64cfb.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c29bd76618e3a9b54058e6aa0e4afa9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b423aa3a82374ac3a3835cd5a385cf5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d83fb9ac8a18e78a4c56da79514b5ccb.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/18/586a77e0-beee-4402-ba3b-d7ed71a7c5b8.png?resizew=152)
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【推荐3】在如图所示的几何体中,四边形
为平行四边形,
平面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b62c231d968cfce1e46f5b9c14836592.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
,
.
平面
;
(2)若
,求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b62c231d968cfce1e46f5b9c14836592.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c118858379800688c993a8b61270b356.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99abeecaf21825d9f1d6f8366699f50a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/342d452a7b850cd3a15b23619ad39bd7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ca58b14f9bbdbc3204f6f330525943.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a4613db540c9cb6a9d7e963bf89c2a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9111c8e64fc183a777dbe0e82c9202cd.png)
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解答题-证明题
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适中
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【推荐1】已知四棱锥
的底面为直角梯形,
,
°,
底面
,且
,
是
的中点.
![](https://img.xkw.com/dksih/QBM/2017/12/8/1834272709189632/1835621563072512/STEM/2db5945665c04b1a9f3d90a354f3cc8a.png?resizew=179)
(1)证明:平面
平面
;
(2)求
与
所成角的余弦值;
(3)求平面
与平面
所成二面角(锐角)的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f79863ffcfa63117ca6741b20a48e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bb8668458bf984e12627c43b694b1be.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/bda1a7eeb84ee2f5f723c78de0867aa1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://img.xkw.com/dksih/QBM/2017/12/8/1834272709189632/1835621563072512/STEM/2db5945665c04b1a9f3d90a354f3cc8a.png?resizew=179)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
(3)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53bdef2e7a7929ad6190302ab44c46c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17c5ef850e256c98ca4f033999e61311.png)
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解题方法
【推荐2】在棱长为2的正方体
中,E,F分别为
,CD的中点.
![](https://img.xkw.com/dksih/QBM/2022/4/25/2965909538267136/2968127410233344/STEM/23785052b7c244c5b50030ce1b31df1b.png?resizew=156)
(1)求
;
(2)求直线EC与AF所成角的余弦值;
(3)求二面角
的余弦值的绝对值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://img.xkw.com/dksih/QBM/2022/4/25/2965909538267136/2968127410233344/STEM/23785052b7c244c5b50030ce1b31df1b.png?resizew=156)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1074d7565e6295b4bb77ff7d2854068c.png)
(2)求直线EC与AF所成角的余弦值;
(3)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a5f8dfb22b415219ba7af3dc7e3d808.png)
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