Вычислите: sin420 градусов, cos 11π: 6, tg31π: 3, ctg(-330градусов)

1)sin 420° = sin(360° + 60°) = sin 60° = √3/2

2)cos 11π/6 = cos(2π - π/6) = cos(-π/6) = cos π/6 = √3/2

3)tg 31π/3 = tg(10π + π/3) = tg π/3 = √3

4)ctg(-330°) = -ctg 330° = -ctg(360° - 30°) = -ctg(-30°) = ctg 30° = √3