User talk:Djskiskyskoski

Great-circle distance
Hi Djskiskyskoski, and welcome to Wikipedia. I just reverted your change at great-circle distance, but thanks for contributing and I hope you'll stick around. I think you got mixed up because the formula there is in terms of latitude $$\phi$$ (angular distance from the equator to a point) rather than colatitude $$\tfrac12\pi - \phi$$ (angular distance from a pole to the point). So if you make s spherical triangle out of the north pole $$\bigl(0, \tfrac12\pi\bigr)$$ and points $$(\lambda_1, \phi_1),$$ $$(\lambda_2, \phi_2),$$ the sides of the triangle are $$a = \tfrac12\pi - \phi_1,$$ $$b = \tfrac12\pi - \phi_2,$$ and $$c,$$ and the included angle is $$C = \lambda_2 - \lambda_1.$$ Stick those into the spherical law of cosines and solve for $$c$$ and you should get the formula at great-circle distance. Cheers! –jacobolus (t) 06:03, 1 August 2023 (UTC)