sin300度=sin(360度-60度)=-sin60度=-√3/2
cos10π/3=cos(4π-2π/3)=-cosπ/3=-1/2
sim11π/4=sin(2π+3π/4)=sin3π//4=sim(π-π/4)=sinπ/4=√2/2
tan(-1560度)=tan(-4X360度-120度)=tan(-120度)=-tan(180度-60度)
=tan60度=√3
sin300=sin(180+120)=-sin120
cos(10π/3)=cos(2π+4π/3)=cos(π+π/3)=-cos(π/3)