вычислите :cos210°+sin120°-tg240°

cos(210)=cos(180+30)=-cos(30)= -√3/2sin(120)=sin(90+30)=cos(30)=√3/2tg(240)=tg(180+60)=tg(60)=√3 -√3/2+√3/2-√3= -√3