化簡(sin^A+tanAtanA/2+cos^A)*sin2A/2cosA
化簡[sin^A+tanA*tan(A/2)+cos^A]*sin2A/2cosA原式=[1 + tanA*tan(A/2) ]*sinA= sinA +tanA*sinA *(1-cosA)/sinA=sinA +tanA*(1-cosA) = tanA 注:tan(A/2) = (1-cosA)/sinA