解题方法
1 . 如图,四棱锥S-ABCD中,SD⊥AD,SD⊥CD,E,F分别是SC,SA的中点,O是底面正方形ABCD的中心,AB=SD=4.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/4/5e6b82da-68dc-4cf8-8ff2-28463ce81e20.png?resizew=186)
(1)求证:EO
平面SAD;
(2)求异面直线EO与BF所成角的余弦值.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/4/5e6b82da-68dc-4cf8-8ff2-28463ce81e20.png?resizew=186)
(1)求证:EO
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb31ef428bd9de9bc875b343feded3c7.png)
(2)求异面直线EO与BF所成角的余弦值.
您最近一年使用:0次
2 . 已知直三棱柱
中,
,
,则异面直线
与
所成角的余弦值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e075468e7fb0bf30229aec01a7205977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3824f8acc6509258fb8a6bc5b35f714d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b470c4e195cf7a07b7a331ce4b436e03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
2019-02-08更新
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562次组卷
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2卷引用:广东省惠州市2019-2020学年高二上学期期末数学试题