Ответ:

sin(750°)=sin(30°+2*360°)=sin(30°)=1/2

ctg(945°)=ctg(45°+5*180°)=ctg(45°)=1

cos(1140°)=cos(60°+3*360°)=cos(60°)=1/2

tg(-495°)=-tg(495°)=-tg(135°+2*180°)=-tg(135°)=-(-1)=1

Получаем: ½+1+½+1=2+1=3