Solution
= Solution
The https://www-thphys.physics.ox.ac.uk/people/AndreiStarinets/TUTORIALS_NOTES_GR/gr-cosmology-exam-paper-2011-solutions.pdf#page=7[official notes, PDF p. 7, handwritten p. 1] derive the affine choice of coordinate time and the circular-orbit angular velocity from the <geodesic equations>.