4sinA+2cosB=1两边平方得,16sinA*sinA+4cosB*cosB+16sinA*cosB=1
2sinB+4cosA=3√3两边平方得4sinB*sinB+16cosA*cosA+16cosAsinB=27两项加:20+16sin(A+B)=28,sin(A+B)=1/2,sin(180-C)=1/2=sinC,C=30或150
4sinA+2cosB=1两边平方得,16sinA*sinA+4cosB*cosB+16sinA*cosB=1
2sinB+4cosA=3√3两边平方得4sinB*sinB+16cosA*cosA+16cosAsinB=27两项加:20+16sin(A+B)=28,sin(A+B)=1/2,sin(180-C)=1/2=sinC,C=30或150