Sin55° cos25° - cos55° sin25° делить sin12° cos18° - sin12° sin18°

Question

Sin55° cos25° - cos55° sin25° делить sin12° cos18° - sin12° sin18°

Comments

в знаменателе косяк...

Answer 1

Sin55° Cos25° - Cos55° Sin25°= Sin(55° - 25°) = Sin30° 
Сos12° Cos18° - Sin12° Sin18° = Cos(12° + 18°) = Cos30°
наш пример:
Sin30°/Cos30° = tg30° = 1/√3