Question

решить уравнение!!
sin^2 x(pi-a) cos^2(pi + a) - 1/4sin^2(2a+3pi)

Answer 1

$sin^2(pi -a)cos^2(pi +a)-frac{1}{4}sin^2(2a+3pi )=sin^2acos^2a-frac{1}{4}sin^22a=\\=(sinacdot cosa)^2-frac{1}{4}sin^22a=(frac{1}{2}sin2a)^2-frac{1}{4}sin^22a=\\=frac{1}{4}sin^22a-frac{1}{4}sin^22a=0$