1) cos 225°=cos(270°-45°)=cos (3/ 2-45°)=-sin 45°=-√2/2
3) tg 330°=tg (360°-30°)=tg (2п-30°)=-tg 30°= -√3/3
1) cos 225°=cos(270°-45°)=cos (3/ 2-45°)=-sin 45°=-√2/2
3) tg 330°=tg (360°-30°)=tg (2п-30°)=-tg 30°= -√3/3