Ответ:
x = 2пn и x = +-2п/3 + 2пn
Пошаговое объяснение:
sin^2 (x/2) - cos^2 (x/2) = cos(-7п - 2x)
(sqrt((1-cosx)/2))^2 - (sqrt((cosx+1)/2)^2 = cos(2x+п)
(1-cosx)/2 - (cosx+1)/2 = -cos(2x)
(1-cosx- cosx-1)/2 = -(2cos^2 (x) - 1)
-2cosx/2 + 2cos^2(x) - 1 = 0
2cos^2 - cosx -1 =0
cos x = 1 cos x = -0,5
x = 2пn x = +-2п/3 + 2пn