Вычислите sin t и cos t , если t=0; 3п/4 ; 7п/6; -2п/3

1) t=0
sin 0=0
cos 0=1

2) t=3π/4
sin(3π/4)=sin(π-π/4)=sin π/4=√2/2
cos(3π/4)=cos(π-π/4)=-cosπ/4=-√2/2

3) t=7π/6
sin 7π/6=sin(π+π/6)=-sin π/6=-1/2=-0.5
cos 7π/6= cos (π+π/6)=-cos π/6=-√3/2

4) t=-2π/3
sin (-2π/3)=-sin 2π/3=-√3/2
cos(-2π/3)=cos2π/3=-1/2=-0.5