Solution
= Solution
Curvature requires a $C^2$ regular curve; torsion requires $C^3$ and nonzero curvature. The parameter-independent formulas are
$$
\boxed{\kappa=\frac{|\gamma'\times\gamma''|}{|\gamma'|^3},\qquad
\tau=\frac{\det(\gamma',\gamma'',d^3\gamma/dt^3)}{|\gamma'\times\gamma''|^2}.}
$$