Question

已知:A,B,C是三角形ABC的内角,a,b,c分别是其对边,向量m=(根号3,cos(兀-A)-1),n=(c

Answer 1

向量m=(√3,-cosA-1),n=(sinA,1).

1)m*n=√3sinA-cosA-1=0,

2sin(A-π/6)=1,

A-π/6=π/6,

A=π/3.

cosBA,sinB>sinA,

sinB=√6/3,

b=asinB/sinA=4√2/3.