1)sin 750°ctg50°+tg(-120°) 4)sin(π-t)+cos(3π+t)>-√3 16 (-55) __ 2)tg __-cos____ 2 3 (6) 3)упростить π ctg(π+α) сos(__+α)

Упростим выражения и вычислим их значения:

1) sin 750° * ctg 50° + tg (-120°) = sin 750° * ctg 50° - tg (120°) = ½ * 0.84 – (-1.73) = 0.84/2 + 1.73 = 0.42 + 1.73 = 1.42 + 0.73 = 2.15;

4) sin (π - t) + cos (3 * π + t )  =  sin (π - t) + cos ( π + t )  =  cos a + (-cos a) = cos a – cos a – cos a * (1 – 1)  = cos a * 0 = 0;

3) ctg (π + α) * сos (pi + α)^2 = ctg (π + α) * сos (pi + α) *  сos (pi + α) = ctg a * (-cos a) * (-cos a) = ctg a * cos a * cos a = cos^3 a/sin a = ctg a * cos^2.