1. Вычислите: a) sin 6; 6) cos (-97); в) tg; г) ctg (-3)

Ответ: a) 0.5; б) -√2/2; в) -1; г) -√3

1. а) \(sin \frac{5\pi}{6} = sin (\pi - \frac{\pi}{6}) = sin \frac{\pi}{6} = \frac{1}{2} = 0.5\)
2. б) \(cos(-\frac{9\pi}{4}) = cos(\frac{9\pi}{4}) = cos(2\pi + \frac{\pi}{4}) = cos(\frac{\pi}{4}) = \frac{\sqrt{2}}{2} \)
3. в) \(tg \frac{5\pi}{4} = tg (\pi + \frac{\pi}{4}) = tg \frac{\pi}{4} = 1\)
4. г) \(ctg(-\frac{\pi}{3}) = -ctg \frac{\pi}{3} = -\frac{\sqrt{3}}{3}\)

Ответ: a) 0.5; б) -√2/2; в) -1; г) -√3