名校
1 . 如图,已知
是直角梯形,且
,平面
平面
,
,
,
,
是
的中点.
![](https://img.xkw.com/dksih/QBM/2020/3/5/2413229531242496/2416047264735232/STEM/568d3f06-89f2-4803-89fb-ece44d2e3ec9.png)
(1)求证:
平面
;
(2)求平面
与平面
所成锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b9d54cbbf601f4583659771eb534997.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5bd5abb17f9b165312476bcafb74657.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c99e6d75d606b5cae9392ecca969200.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edc306485b010bdec4281bc68909c08b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6f6923bc38131265bed394a3b38937e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/326a6b980171b22f89721798e76837ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://img.xkw.com/dksih/QBM/2020/3/5/2413229531242496/2416047264735232/STEM/568d3f06-89f2-4803-89fb-ece44d2e3ec9.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c99cda5a272bbe32b28575fa51b9f6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62871bb0dff211fc3bd80f9066c25b29.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65277734669566578cbb7d690bb200fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
您最近一年使用:0次
2020-03-09更新
|
307次组卷
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2卷引用:重庆市永川北山中学校2023届高三上学期期末数学试题