三角形ABC中,{sin(A-B)+sinC)/{cos(A-B)+cosC}=根号3/3(1)求B(2)若asinB=根号3sinA,求a+c的最大值
问题描述：
三角形ABC中,{sin(A-B)+sinC)/{cos(A-B)+cosC}=根号3/3
(1)求B(2)若asinB=根号3sinA,求a+c的最大值
答
buzhidao
答
,{sin(A-B)+sinC)/{cos(A-B)+cosC}=,{sin(A-B)+sin(A+B))/{cos(A-B)-cos(A+B)}=2sinAcosB/2sinAsinB=cosB/sinB=√3/3B=30°.a/sinA=b/sinB=c/sinC,asinB=bsinA=√3sinA,b=√3.a+c=2√3(sinA+sinC)=4√3sin[(A+C)/2]c...