1 . 如图,底面
是边长为1的正方形,
平面
,
,
与平面
所成角为60°.
平面
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8d2d217e9bcd059908f117dfc4d4259.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5852b8f3ecf394b98074432eafafbf84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e56fdf217165748fafe938b64fa08179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f717b7d4d0978eec7330afec554c078.png)
您最近一年使用:0次
2019-05-07更新
|
1482次组卷
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13卷引用:广东省惠州市2021届高三上学期第一次调研数学试题
广东省惠州市2021届高三上学期第一次调研数学试题广东省佛山市第四中学2021届高三上学期8月开学考试数学试题2016届黑龙江省双鸭山一中高三上学期期中理科数学试卷河北省衡水市2018届高三高考模拟联考理数试题吉林省辽源市田家炳高级中学等五校2018届高三上学期期末联数学(理)试题辽宁省抚顺中学2017-2018学年高三上学期期末考试理科数学试题广东省佛山市南海区狮山石门高级中学2020-2021学年高二上学期第二次统考数学试题上海市大同中学2021届高三上学期开学考试数学试题宁夏吴忠市2022届高三一轮联考数学(理)试题2015-2016学年河北省广平县一中高二上学期第四次月考理科数学试卷2016-2017学年河北冀州中学高二理上学期月考四数学试卷【全国百强校】贵州省铜仁市第一中学2018-2019学年高二下学期期中考试数学(理)试题内蒙古赤峰二中2020-2021学年高二上学期第一次月考数学(理科)试题
2014·广东湛江·一模
名校
解题方法
2 . 在如图所示的几何体中,四边形
为平行四边形,
,
平面
,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/2014/4/28/1571681095139328/1571681100988416/STEM/d2fd3c26c0c84c68ab2b1ec536cbb2ac.png?resizew=217)
(1)若
是线段
的中点,求证:
平面
;
(2)若
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ed8f7d3d7043d4b1eb98fc5c4e2fcd3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed04b01505bbd8a4ac0bc12e46f23bf6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e41d3f7d55fcbaebc4e2450ac63a3dc5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9c30de91ed42df92510cb64548fe704.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c05f315ab14567942f699983b60d04be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed6034301fc4110da89bdb0f46ad82ab.png)
![](https://img.xkw.com/dksih/QBM/2014/4/28/1571681095139328/1571681100988416/STEM/d2fd3c26c0c84c68ab2b1ec536cbb2ac.png?resizew=217)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6895bdd0286b8e2704fee9c343d82f57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/369eb8ad56da7dc1cdb7c43762be4bee.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a9cd88984f891a49ab451a06410a1f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4b820c84570da9c38d0a81c22788b76.png)
您最近一年使用:0次
2016-12-02更新
|
1477次组卷
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3卷引用:2014届广东省湛江市高三高考模拟测试二理科数学试卷
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