SinB * CosC = （根号3）/4SinA=（根号3）/2CosA=1/2SinB * CosC = Sin(A+C) * CosC = SinA * Cos²C + CosA * CosC * SinC = （根号3）/4∴（2根号3）* Cos²C + 2 * CosC * SinC =根号3∴（根号3）*(2*Cos...