Найдите значение выраженич 6 sin 17п/12*cos 17п/12

По формуле синуса двойного угла

sin2α=2·sinα·cosα

6·sin(17π/12)·cos(17π/12) =
=3·2·sin(17π/12)·cos(17π/12)=3·sin(34π/12)=
=3·sin((24π/12) + (10π/12))=3sin (2π+(5π/6))=3 sin (5π/6)=
=3·sin (π/6)=3·(1/2)=3/2=1,5