名校
1 . 如图,在梯形
中,
,
,
,现将
沿
翻折成直二面角
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/5/381bc715-77fe-4609-938a-ada15fa13cc5.png?resizew=468)
(Ⅰ)证明:
;
(Ⅱ)若异面直线
与
所成角的余弦值为
,求二面角
余弦值的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68d31600cba2d5256c7e78b6122d6755.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6de3595bb7c79503fabd75d99196ccb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbced129627233661d88e9663a9e13c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf29d07c3751c41ab3503065a5a5052e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/5/381bc715-77fe-4609-938a-ada15fa13cc5.png?resizew=468)
(Ⅰ)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec82279b14a119057fdd78b85d63e669.png)
(Ⅱ)若异面直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56d266a04f3dc7483eddbc26c5e487db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12a4bddf1ea3c5d37f2233a4821909e9.png)
您最近一年使用:0次
2019-01-22更新
|
3814次组卷
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4卷引用:【市级联考】福建省宁德市 2019届高三第一学期期末质量检测数学理科试题
2 . 如图,棱长为
的正方体的顶点
在平面
内,三条棱
,
,
都在平面
的同侧. 若顶点
,
到平面
的距离分别为
,
,则平面
与平面
所成锐二面角的余弦值为________
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7ffe8515ff6183c1c7775dc6f94bdb8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://img.xkw.com/dksih/QBM/2017/9/4/1766885189820416/1768189697097728/STEM/f010708993524f86b20b3fde0d7be584.png?resizew=16)
![](https://img.xkw.com/dksih/QBM/2017/9/4/1766885189820416/1768189697097728/STEM/30ec87ec-8bfa-42af-9096-20f02a40f4c5.png?resizew=192)
您最近一年使用:0次
2017-09-06更新
|
3033次组卷
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3卷引用:浙江省名校协作体2018届高三上学期联考数学试题
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