11.cos(3,5p)=cos270°= 0
12.tg(5p/4)tg225°=tg(270°-45°)=ctg45°=1
13.cos(5p/3)=cos300°=cos(270°+30°)=sin30°=1/2
14.sin(10p/3)=sin600°=sin240°=sin(270°-30°)=-cos30°=-√3/2
15. cos(-960)=cos240°=cos(270-30)=-sin30=-1/2
16.tg750°=tg30°=√3/3
17.ctg1110°= ctg30°=√3
18.sin(-13p/3)=-sin60°=-√3/2
19.ctg(-13p/6)=ctg390°=-ctg30°=-√3
20.cos(-29p/4)=cos1305°=cos225°=cos(270°-45°)=-sin45°=-√2/2
