△ABC中,(a^2+b^2)sin(A-B)=(a^2-b^2)sin(A+B),试判断△ABC的形状.答案是这样写的:由题知:a^2[sin(A+B)-sin(A-B)]=b^2[sin(A+B)+sin(A-B)] 所以 a^2sosAsinB=b^2sinAcosB怎么化简的?
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![△ABC中,(a^2+b^2)sin(A-B)=(a^2-b^2)sin(A+B),试判断△ABC的形状.答案是这样写的:由题知:a^2[sin(A+B)-sin(A-B)]=b^2[sin(A+B)+sin(A-B)] 所以 a^2sosAsinB=b^2sinAcosB怎么化简的?](/uploads/image/z/10139428-28-8.jpg?t=%E2%96%B3ABC%E4%B8%AD%2C%28a%5E2%2Bb%5E2%29sin%28A-B%29%3D%28a%5E2-b%5E2%29sin%28A%2BB%29%2C%E8%AF%95%E5%88%A4%E6%96%AD%E2%96%B3ABC%E7%9A%84%E5%BD%A2%E7%8A%B6.%E7%AD%94%E6%A1%88%E6%98%AF%E8%BF%99%E6%A0%B7%E5%86%99%E7%9A%84%EF%BC%9A%E7%94%B1%E9%A2%98%E7%9F%A5%EF%BC%9Aa%5E2%5Bsin%28A%2BB%29-sin%28A-B%29%5D%3Db%5E2%5Bsin%28A%2BB%29%2Bsin%28A-B%29%5D+%E6%89%80%E4%BB%A5+a%5E2sosAsinB%3Db%5E2sinAcosB%E6%80%8E%E4%B9%88%E5%8C%96%E7%AE%80%E7%9A%84%3F)
△ABC中,(a^2+b^2)sin(A-B)=(a^2-b^2)sin(A+B),试判断△ABC的形状.答案是这样写的:由题知:a^2[sin(A+B)-sin(A-B)]=b^2[sin(A+B)+sin(A-B)] 所以 a^2sosAsinB=b^2sinAcosB怎么化简的?
△ABC中,(a^2+b^2)sin(A-B)=(a^2-b^2)sin(A+B),试判断△ABC的形状.答案是这样写的:由题知:
a^2[sin(A+B)-sin(A-B)]=b^2[sin(A+B)+sin(A-B)] 所以 a^2sosAsinB=b^2sinAcosB
怎么化简的?
△ABC中,(a^2+b^2)sin(A-B)=(a^2-b^2)sin(A+B),试判断△ABC的形状.答案是这样写的:由题知:a^2[sin(A+B)-sin(A-B)]=b^2[sin(A+B)+sin(A-B)] 所以 a^2sosAsinB=b^2sinAcosB怎么化简的?
解sin(A+B)-sin(A-B)=sinAcosB+cosAsinB-(sinAcosB-cosAsinB)=2cosAsinB
即sin(A+B)+sin(A-B)=sinAcosB+cosAsinB+(sinAcosB-cosAsinB)=2sinAcosB
即a^2[sin(A+B)-sin(A-B)]=b^2[sin(A+B)+sin(A-B)]
得 a^2sosAsinB=b^2sinAcosB
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△ABC中,(a^2+b^2)sin(A-B)=(a^2-b^2)sin(A+B),试判断△ABC的形状.答案是这样写的:由题知:a^2[sin(A+B)-sin(A-B)]=b^2[sin(A+B)+sin(A-B)] 所以 a^2sosAsinB=b^2sinAcosB怎么化简的?
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