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已知a,b,c分别是△ABC的三个内角A,B,C所对的边,若a=1,b=,三内角...
已知a,b,c分别是△ABC的三个内角A,B,C所对的边,若a=1,b=
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225710086185255/SYS201311012257100861852010_ST/0.png)
,三内角A,B,C成等差数列,则sinA=
.
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