ctg300 sin135 tg150 cos240

1)Ctg300 = -tg ( 3π/2+π/6)=-tg π/6=-1/√3
2)sin135=sin(π-π/4)=sin π/4=√2/2
3)tg150=-tg(π-π/6)=-tg π/6=-1/√3
4)cos240=cos(π+π/3)=-cos π/3 = -√3