Texts: 5.1 It is shown in the text that the covariant derivative of a vector is given by
∇u + Γikuk ∇vi Ui:j= Thuk
It is also shown that the metric is constant under covariant differentiation so that it can be moved through the derivative to raise and lower indices. Thus
gik(h)=vi;
Use this relation to derive the second of the above equations from the first.