Question

Вычислите:
1) cos 225°
2) tg 330°

Answer 1

1) cos 225°=cos(270°-45°)=cos (3π/2-45°)=-sin 45°=-√2/2

2) tg 330°=tg (360°-30°)=tg (2π-30°)=-tg 30°= - √3/3