m·n=(-1,√3)·(cosA,sinA)=√3sinA-cosA=2sin(A-π/6)=1即：sin(A-π/6)=1/2A是内角,故：A∈(0,π)即：A-π/6∈(-π/6,5π/6)故：A-π/6=π/6即：A=π/3(1+sin(2B))/(cosB^2-sinB^2)=(sinB+cosB)^2/((cosB+sinB)(c...