把正方形纸片
沿对角线
折成
的二面角,则折纸后
与
所成角的余弦值为______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6256551ef7963bea4efec83f4797a1ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
更新时间:2022-10-24 23:34:17
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【推荐1】已知在三棱锥S-ABC中,SA⊥底面ABC,AB⊥BC,SA=AB=BC,则异面直线SC与AB所成角的余弦值为______ .
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①
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