1)-5sin 60° + 2= -5 *√3/2 +2
2)4sin 2 х + 5 + 4 cos 2 х =4sin^ 2 х + 5 + 4 cos ^2 х =
4(sin^ 2 х +cos ^2 х) +5= 9
3)соs 2 х (1- tg x) (1+tg x)= соs ^2 х (1- tg ^2x) =
соs ^2 х (1- sin ^2x/ cos^2x) = соs ^2 х (cos^2x -sin^2x)/соs ^2 х=
(cos^2x -sin^2x) = cos2x
4)sin2(2700- α) + sin2(3600- α) +ctg3(3600- α)-tg3(900+ α) =
sin^2(270- α) + sin^2(360- α) +ctg^3(360- α) - tg^3(90+ α) =
cos^2a +sin^2a - ctg ^3a +ctg ^3a= 1