Вычислите 1)Sin (-13pi/4) 2)Cos (13pi/6) 3)tg (-19pi/6) 4)ctg (7pi/4) Решите уравнения 1)Sin t=-√2/2 2)Cos t=0

1) Sin (-13pi/4) = Sin ((-8pi/4) - 5pi/4) = Sin (-2pi - 5pi/4) = Sin (- 5pi/4) = Sin (2pi- 5pi/4)= Sin (3pi/4) = √2/22) Cos (13pi/6) = Cos (12pi/6 + pi/6) = Cos (2pi + pi/6) = Cos (pi/6) = √3/23) tg (-19pi/6) = tg ((-12pi/6) - 7pi/6) = tg (-7pi/6) = tg (2pi - 7pi/6) = tg (5pi/6) = -√3/34) ctg (7pi/4) = ctg (2pi - 7pi/4) = ctg (-pi/4) = -1Решение уравненийhttp://bit.ly/2vaSEgU