Вычислите cos 5π/3 tg (-5π/6) tg π ctg π/4+cos π/2 sin (-2π/3) sin 150°-cos720° + tg225° : з

1) Cos5π/3 = Cos(2π - π/3) =  Cosπ/3 = 1/2
2) tg(- 5π/6) = - tg(π - π/6) = tgπ/6 = 1/√3 = √3/3
3) tgπ*ctgπ/4 + Cosπ/2*Sin(-2π/3) = 0*1- 0*Sin2π/3 = 0
4) Sin150° - Cos720° + tg225° = Sin(180 - 30) - Cos(2*360 +0) + tg(270 - 45) =
= Sin30° - Cos0 + ctg45°= 1/2 - 1 + 1 = 1/2 = 0,5

мы просто вычисляем значение используя таблицу значений тригонометрических функций


sin(150°)-cos(720°)+tan(225°)=1/2-1+1=1/2=0,5