The cosine formula from spherical trigonometry gives the angular separation between two points on the surface of a sphere, where the apex of the angle is at the center of the sphere. If the two points...The cosine formula from spherical trigonometry gives the angular separation between two points on the surface of a sphere, where the apex of the angle is at the center of the sphere. If the two points have latitudes ϕ1 and ϕ2 and longitudes L1 and L2, then the cosine formula gives the angular separation of the two points θ :
