1 . 如图,在平行四边形
中,
,将
沿对角线
折起,折后的点
变为
,且
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cb16a791ce234a13ec793867b64724b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab2a2834d80ff574e79eae8ca8d4e94f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00135791b38a81a8db0c228bfddbdc62.png)
(Ⅰ)求证:平面平面
;
(Ⅱ)求异面直线与
所成角的余弦值;
(Ⅲ)E为线段上的一个动点,当线段
的长为多少时,
与平面
所成的角正弦值为
?
您最近一年使用:0次
2019-07-15更新
|
1035次组卷
|
2卷引用:贵州省安顺市黄果树高级中学2022-2023学年高二上学期第一次月考数学试题
2 . 如图,在四棱锥
中,底面
是矩形,平面
平面
,
为
的中点,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/26/5c3e6154-6d80-4b7b-9415-8147ce5ec61a.png?resizew=169)
(1)证明:平面
平面
;
(2)求三棱锥
的体积.
![](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/e4aa9084b8fe0fe05c4388d1f835587b.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/01b5fdbef7ac8859e74fd1d79cb47392.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db86a481972bd2dc553889617002d146.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/26/5c3e6154-6d80-4b7b-9415-8147ce5ec61a.png?resizew=169)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39282bdf319f30d7bc261e2e3ab3b1e4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3df5935c893580c77ab6fa6eb0a70bdb.png)
(2)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bf9718967af7a01c5b4866ea6f73bbb.png)
您最近一年使用:0次
2021-04-09更新
|
107次组卷
|
2卷引用:贵州省安顺学院附属高级中学2021届高三上学期阶段性检测数学(文)(三)试题