вычислить cos( – π / 6) × sin( – π / 3) + tg( – π / 4)
cos( – π/6) × sin( – π/3) + tg( – π/4) = =cos( π/6) × (-sin( π / 3)) - tg(π/4)= =(√3/2) ×(-√3/2)-1=(3/4)-1=-1/4.