解题方法
1 . 在直三棱柱
中,
,
,
、
分别为棱
、
的中点,点
在棱
上.
![](https://img.xkw.com/dksih/QBM/2017/2/16/1625387384979456/1625923945103360/STEM/6817f962-d2d2-4b16-b3db-01c970e6acfd.png?resizew=162)
(1)证明:直线
平面
;
(2)若
为棱
的中点,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb717228e1762d335814a3adc90eae45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.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/2017/2/16/1625387384979456/1625923945103360/STEM/6817f962-d2d2-4b16-b3db-01c970e6acfd.png?resizew=162)
(1)证明:直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c4f95dad4c29bcad7f621c453007a3e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08052a312e4a29b6840a78850d666d92.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/610038cde1968e0a15792ce77dd0e99f.png)
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2017-02-17更新
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3卷引用:贵州省兴仁市凤凰中学2020-2021学年高一下学期第四次月考数学试题