Question

2sin(x+П/4)*sin(x-5п/6) помогите решить

Answer 1

$2* \frac{1}{2} (cos(x+ \frac{ \pi }{4}-x+ \frac{5 \pi }{6} )-cos(x+ \frac{ \pi }{4}+x- \frac{5 \pi }{6} )=cos( \pi + \frac{ \pi }{12} )-$$cos(2x- \frac{7 \pi }{12} )= - cos \frac{ \pi }{12} -cos(2x- \frac{7 \pi }{12} )= - cos \frac{ \pi }{12} +sin( \frac{ \pi }{12} -2x)$