Sin(3x-п/4)sin(2x+п/4)-1/2sinx

Question

Sin(3x-п/4)sin(2x+п/4)-1/2sinx

Answer 1

sin(3x-п/4)sin(2x+п/4)-1/2sinx=1/2[cos(x-П/2)-cos(5x)]-1/2sinx=

=-1/2cos5x