1 . 在四棱锥P-ABCD中,四边形ABCD是直角梯形,
底面
,
,
,
是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/5/2dc17b58-a435-470d-a364-19aaa070a162.png?resizew=172)
(1)求证:平面
平面
;
(2)若
与平面
所成角的正弦值为
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/381ed6f77b4c34d9e30126ce27fe194c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c595394c41ec1d5a40554ea8a86e845.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/5/2dc17b58-a435-470d-a364-19aaa070a162.png?resizew=172)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/677d1863ff4d8ac1604b18149d4f320f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c66d99a6a8415ddad22bbed33b64cfb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24c14ff9b66f21c05e52dc3c8908c2df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5102c216393e133fa25dba98cd78535.png)
您最近一年使用:0次
2 . 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
3 . 如图,三棱柱
的侧棱垂直于底面,各条棱长均为2,
,
分别为
,
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/5/8c2fd9b1-3623-415d-bdf7-c35a9809c673.png?resizew=151)
求证:(1)
平面
;
(2)平面
平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/5/8c2fd9b1-3623-415d-bdf7-c35a9809c673.png?resizew=151)
求证:(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d447ce2833cac5260ed5532283fa3997.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/770b4f16694b2bd79a1a93d776a82680.png)
(2)平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e812484073ca4a6fd647021fc72d57e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bea124cef7ab3fd8069243e9894d1c59.png)
您最近一年使用:0次
2019-04-12更新
|
586次组卷
|
2卷引用:【全国百强校】贵州省思南中学2018-2019学年高二3月月考数学(文)试题
4 . 如图,在底面是正方形的四棱锥中
,
,
点
在底面
的射影
恰是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/6/41744164-3a95-474c-8d48-384b26e198a8.png?resizew=160)
(1)证明:平面
平面
;
(2)求二面角
的正弦值大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/364d6c88726d8c3bb8ed297057332bac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/6/41744164-3a95-474c-8d48-384b26e198a8.png?resizew=160)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b33b7213d99a817bff19bcf740a0697c.png)
您最近一年使用:0次
2019-01-08更新
|
1413次组卷
|
3卷引用:【校级联考】贵州省贵阳第一中学、云南师大附中、广西南宁三中2019届高三“3 3 3”高考备考诊断联考数学(理)试题