How to show the continuity

35 Views Asked by At

Below picture is from the Jost's Riemannian Geometry. At last ,I don't know how get the homotopy. It is not proved that $c_s(t)$ is continue for any $s$. So I can't get the $\Gamma(t,s)$ is continue.How to prove it ?

enter image description here

enter image description here