仅供参考
∵√3sinCcosC-(cosC)^2=1/2(√3/2)sin2C-(1/2)(cos2C+1)=1/2(√3/2)sin2C-(1/2)cos2C=1sin2Ccosπ/6-cos2Csinπ/6=1sin(2C-π/6)=1∵C是三角形的内角∴2C-π/6=π/2∴C=π/3
