1) Cos135=cos (90+45) =sin45= V2/2
2) Sin 8П/3=sin(2П/3+2П) =sin 2П/3= V3/2
3) tg 7П/3=tg (П/3+2П)=tg=V3
4) Cos^2 П/8-sin^2 2П/8=cos П/4=V2/2
1) Cos135=cos (90+45) =sin45= V2/2
2) Sin 8П/3=sin(2П/3+2П) =sin 2П/3= V3/2
3) tg 7П/3=tg (П/3+2П)=tg=V3
4) Cos^2 П/8-sin^2 2П/8=cos П/4=V2/2