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如图所示,CD是一个平面镜,光线从A点射出经CD上的E点反射后照射到B点,设入射...
如图所示,CD是一个平面镜,光线从A点射出经CD上的E点反射后照射到B点,设入射角为α(入射角等于反射角),AC⊥CD,BD⊥CD,垂足分别为C,D.若AC=3,BD=6,CD=12,则tanα的值为( )
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402570596262/SYS201311031014025705962006_ST/images0.png)
A.
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B.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402570596262/SYS201311031014025705962006_ST/1.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402570596262/SYS201311031014025705962006_ST/2.png)
D.
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