1 . 如图,
平面
,
∥
,
,
,点
是
的中点,连接
.
∥平面
;
(2)求
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca5dd496ee0c1170ef6dcc48266ee444.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/354c20e085fe1a99a8be03bd1d16b2f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29bea52ad6771c9a15dc74a027b258ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc5adb5eb60ae4435a12d93854066298.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc5adb5eb60ae4435a12d93854066298.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc5adb5eb60ae4435a12d93854066298.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
您最近一年使用:0次
2024-06-02更新
|
893次组卷
|
2卷引用:广西河池市2024届普通高中毕业班适应性模拟测试数学试题
名校
2 . 如图,在四棱锥
中,
平面ABCD,四边形ABCD是菱形,
,
,E是PB上任意一点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/24/581c5ac5-aba7-4df4-80b6-a2337cdc78dd.png?resizew=230)
(1)求证:
;
(2)已知二面角
的余弦值为
,若E为PB的中点,求EC与平面PAB所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bb5b12692517a39c320f99a479eb055.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1719410d21e3de1242366ce2965e838c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/24/581c5ac5-aba7-4df4-80b6-a2337cdc78dd.png?resizew=230)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b757706eee506a078fc25e3f33a70cb.png)
(2)已知二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c5651e38293e0c42a7278af69fa53ae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83303d3784492506fc44f2b4d6b07bc1.png)
您最近一年使用:0次
2022-09-29更新
|
1062次组卷
|
12卷引用:广西2023届高三上学期开学摸底考试数学(理)试题
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