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1 . 如图所示,在球
的内接八面体
中,顶点
,
分别在平面
两侧,且四棱锥
与
都是正四棱锥.设二面角
的平面角的大小为
,则
的取值可能为( ).
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/3/ac4f34b2-80de-4098-a525-a64d496111e9.png?resizew=160)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73cbd9eb22f75ad5304d8491b314a9a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55c6caa0455442437177ab9b995df37b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23f96627abd793ca157d4dd1587f584d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43660b1543b3a2b46185f7629d28a963.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/3/ac4f34b2-80de-4098-a525-a64d496111e9.png?resizew=160)
A.![]() | B.3 | C.![]() | D.1 |
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解题方法
2 . 在
中,
,则角
等于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29addda5749876ddd97aa2426f02fb5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
2020-02-11更新
|
846次组卷
|
3卷引用:天津市红桥区2019-2020学年高一上学期期末数学试题
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3 . 已知
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7741cbc666e68aa4beb0087a6cd7ade0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaa3d3ca8ae9c034b384ba8267808553.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
4 . 已知
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/408cc3b706ea1053cd5104700771c793.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17f6c0ffec7c33c6528f1a76bec1f63f.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
2019-12-16更新
|
780次组卷
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3卷引用:2019年11月中学生标准学术能力诊断性测试测试文科数学试题(一卷)
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5 . 如图所示,合肥一中积极开展美丽校园建设,现拟在边长为0.6千米的正方形地块
上划出一片三角形地块
建设小型生态园,点
分别在边
上.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/5/71886729-eb46-4b62-9618-1ccb10024ad5.png?resizew=135)
(1)当点
分别时边
中点和
靠近
的三等分点时,求
的余弦值;
(2)实地勘察后发现,由于地形等原因,
的周长必须为1.2千米,请研究
是否为定值,若是,求此定值,若不是,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70db40c42655327adee01caedfc9d50c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7789a500686c7a73770404ead6af0590.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9df7fc746f8c4801d8f2f0471ba3297e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/5/71886729-eb46-4b62-9618-1ccb10024ad5.png?resizew=135)
(1)当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7789a500686c7a73770404ead6af0590.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52f8eff113ca3f0d0200253c7c2f5a7a.png)
(2)实地勘察后发现,由于地形等原因,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5a9fc2dda89829fa2c610a8fce86d22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52f8eff113ca3f0d0200253c7c2f5a7a.png)
您最近一年使用:0次
2019-10-14更新
|
1258次组卷
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3卷引用:安徽省合肥一中2019-2020学年9月高三阶段性检测考试数学(理)
名校
6 . 如图①,这个美妙的螺旋叫做特奥多鲁斯螺旋,是由公元5世纪古希腊哲学家特奥多鲁斯给出的,螺旋由一系列直角三角形组成(图②),第一个三角形是边长为
的等腰直角三角形,以后每个直角三角形以上一个三角形的斜边为直角边,另一个直角边为
.将这些直角三角形在公共顶点处的角依次记为
则与
最接近的角是
参考值:
,
,
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52881be613aa404e553da30d8987cfad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e3288a912785af78aae799c17c72ed7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/345204b5c29bb7152eabe67c7d2c9bb9.png)
参考值:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a8fa5bb224274c16673d45ca2207638.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c918b61aa81a544a155ec388c5073ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3c3e90630c11726696e03aefadaf5ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52881be613aa404e553da30d8987cfad.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/14/2320b4b5-099d-4e89-9fce-f232baefaac2.png?resizew=447)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
2018-12-13更新
|
570次组卷
|
3卷引用:【全国百强校】黑龙江省哈尔滨市第六中学2019届高三12月月考数学(文)试题