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已知△ABC的三个角A,B,C所对的边分别为a,b,c且满足根号三倍acosB=bsinA

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已知△ABC的三个角A,B,C所对的边分别为a,b,c且满足根号三倍acosB=bsinA
(1)求B的大小 (2)求cosA-根号3倍sin(C-π/3)的取值范围
已知△ABC的三个角A,B,C所对的边分别为a,b,c且满足根号三倍acosB=bsinA
a/sinA = b/sinB = 2R
a = 2R sinA ,b = 2RsinB
tanB = 根3 ,B = π/3
cosA-根号3倍sin(C-π/3)= cosA-根号3倍sin(π - A -B-π/3)
=cosA-根号3倍sin(π/3 - A) = cosA - 根3 *【sinπ/3cosA-sinAcosπ/3]
= 根3 /2 * sinA - 1/2 *cosA =sin(A - π/3)