根号3 sinA+cosA=根号3√3/2sinA+1/2cosA=√3/2sinAcosπ/6+cosAsinπ/6=√3/2sin(A+π/6)=√3/2A∈(0,π)A+π/6=2π/3或π/3A=π/2或π/6选D
a。