名校
1 . 如图,在四棱锥
中,底面
是矩形,
平面
,
为
上的动点.
![](https://img.xkw.com/dksih/QBM/2021/1/26/2644485862883328/2645412115054592/STEM/a9bfcc08-2dd9-4285-ba56-c379d89e954b.png?resizew=255)
(1)若
平面
,请确定点
的位置,并说明理由.
(2)设
,
,若
,求二面角
的正弦值.
![](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/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://img.xkw.com/dksih/QBM/2021/1/26/2644485862883328/2645412115054592/STEM/a9bfcc08-2dd9-4285-ba56-c379d89e954b.png?resizew=255)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa69a2247ad4d5231aa361349b12f97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46e2da608b66c9aee03e2503388ba4fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9b5d2943803894bc5d204e75e2d172b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0d5a2cd05e4476fc72271e8fdb59a9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b51471daa86588d2f24b364953a66e2a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5102c216393e133fa25dba98cd78535.png)
您最近一年使用:0次
2021-01-27更新
|
667次组卷
|
5卷引用:广西河池市2020-2021学年高二上学期期末数学(理)试题
名校
2 . 如图,在四棱锥
中,底面
为边长为3的正方形,
,
,平面
平面
,
为
的中点,
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/326f9648-d4d1-44ef-8e37-4f7c5c75ea17.png?resizew=198)
(Ⅰ)求证:
平面
;
(Ⅱ)求二面角
的余弦值.
![](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/15721f71a6c8b071ff621f2ffe73e977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/71826134c3080aa75becc655a9089855.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f3e2bed5ce5fe466395d2f5743d335b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/326f9648-d4d1-44ef-8e37-4f7c5c75ea17.png?resizew=198)
(Ⅰ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57f9d682e5d3cc8573574d8d11636758.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(Ⅱ)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ecc407e2b3e9da16eba881fd7a83845a.png)
您最近一年使用:0次
2020-07-25更新
|
610次组卷
|
6卷引用:广西河池市2020-2021学年高三上学期期末数学(理)试题
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