名校
解题方法
1 . 如图,已知正三棱柱
中,所有棱长均为2,点E,F分别为棱
,
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/17/d1da7309-f913-43e5-b38e-71b659098164.png?resizew=217)
(1)求
与平面AEF所成角的正弦值;
(2)过A、E、F三点作一个平面,则平面AEF与平面
有且只有一条公共直线,在图中作出这条公共直线,简略写清作图过程,并求这条公共直线在正三棱柱底面
内部的线段长度.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/17/d1da7309-f913-43e5-b38e-71b659098164.png?resizew=217)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ce1b066f8869d0ff4513f7a99745125.png)
(2)过A、E、F三点作一个平面,则平面AEF与平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99b16cff607cdc2d69afc70dc778acbb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4310db23fc79936c7182361e652bab1a.png)
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名校
2 . 如图,在正方体
的上底面内有一点
,点
为线段
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/12/adda15ef-8579-4697-922c-29122f2bbc33.png?resizew=181)
(1)经过点
在上底面画出一条线
与
垂直,并说明画出这条线的理由;
(2)若点
为线段
靠近
的三等分点,求
与平面
所成角的正切值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/12/adda15ef-8579-4697-922c-29122f2bbc33.png?resizew=181)
(1)经过点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
(2)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1241216f3c1cb5e73043dd1037f556d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7865126ef23077f3ed6832899a600732.png)
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