sin240^0
cos 120^0
tg 240^0
ctg 300^0
źródło:
sin240^0=sin(180^0+60^0)=-sin60^0=-\frac{\sqrt3}{2}
cos 120^0=cos(180^0-60^0)=-cos60^0=-\frac{1}{2}
tg 240^0=tg(180^0+60^0)=tg60^0=\sqrt3
ctg 300^0=ctg(360^0-60^0)=-ctg60^0=-\frac{\sqrt3}{3}