dUd1ec 1 tg-210=-tg(180+30)=-tg30=[tex] \sqrt{3} [/tex]/32 ctg5p/3=ctg((6p-p)/3)=ctg(2p-p/3)=ctg(-p/3)=-[tex] \sqrt{3} [/tex]/33 sin870=sin(360*2+150)=sin(150)=sin(180-30)=sin30=1/24 cos(-8p/3)=cos((6p+2p)/3)=cos(2p+2p/3)=cos2p/3=cos120=cos(90+30)=-[tex] \sqrt{3} [/tex]/3