Question

решить 4sin5п/12*sinп/12

Answer 1

4sin(5п/12)*sin(п/12)=4sin(6п/12-п/12)*sin(п/12)=4sin(п/2-п/12)*sin(п/12)=
4cos(п/12)*sin(п/12)=2sin(п/6)=2·(1/2)=1