sin (11π/3)=sin(4π-π/3)=-(-sin π/3)怎么算的,sin (11π/3)=sin (12π-π)/3=sin(4π-π/3)=sin(-π/3)=-sin(π/3);因此题中所说的:“sin11派/3=sin(4派-(派/3))=-(-sin(派/3))”是错的:应改成:“sin11...