1) cos 765 градусов = cos (765 - 720) = cos 45 градусов = √2 / 2
2) sin (19π / 6) = sin (3π + π / 6) = -sin (π / 6) = -1/2
1) cos 765 градусов = cos (765 - 720) = cos 45 градусов = √2 / 2
2) sin (19π / 6) = sin (3π + π / 6) = -sin (π / 6) = -1/2