cos24°*cos36°-sin24°*cos54°等于多少,
问题描述：
cos24°*cos36°-sin24°*cos54°等于多少,
答
=cos24sin54-sin24cos54=sin（54-24）=sin30=1/2
答
cos24°*cos36°-sin24°*cos54° =cos24°*sin54°-sin24°*cos54° =sin(54°-24°) =sin30° =0.5
答
cos24cos36-sin24cos54=cos24cos36-sin24sin36=cos(24+36)=cos60=1/2