I'm trying to use the tensor formulation of GR to calculate the velocity of a particle in a circular orbit around a black hole. Here is the work I have done so far. What concerns me is that I end up getting zero velocity when applying the metric to the differential equations I get from the geodesic equation. I wonder if I have made a miscalculation, but I am unable to find any, so maybe there is a misunderstanding on my part. Any help is appreciated.