Question

УПРОСТИТЕ ВЫРАЖЕНИЕ!!!!!!!!!

Answer 1

$2Sin(3 pi + frac{x}{2})Cos(4 pi - frac{x}{2})=2Sin( pi + frac{x}{2})Cos frac{x}{2} =-2Sin frac{x}{2} Cos frac{x}{2}=$$-Sinx\\-Sin30 ^{o}=- frac{1}{2}$