Вычислите ctg(-765 градусов)-2 cos(19Пи/3)
Ctg(-765°) - 2cos(19π/3) = ctg(-765° + 720°) - 2cos(19π/3 - 18π/3) = = ctg(-45°) + 2cos(π/3) = -1 + 2*0,5 = -1 + 1 = 0 Ответ: 0