Solution
= Solution
For unit speed on an oriented surface,
$$
T'=\kappa_n n+\kappa_g(n\times T).
$$
These coefficients are normal and <geodesic curvature>; the curve is geodesic iff $\kappa_g=0$.
= Solution
For unit speed on an oriented surface,
$$
T'=\kappa_n n+\kappa_g(n\times T).
$$
These coefficients are normal and <geodesic curvature>; the curve is geodesic iff $\kappa_g=0$.