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在△ABC中,sinA:sinB:sinC=3:2:4,则cosC的值为( ) ...
在△ABC中,sinA:sinB:sinC=3:2:4,则cosC的值为( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101224701181925077/SYS201311012247011819250006_ST/0.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101224701181925077/SYS201311012247011819250006_ST/1.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101224701181925077/SYS201311012247011819250006_ST/2.png)
D.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101224701181925077/SYS201311012247011819250006_ST/3.png)
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