Arc-length parametrization
= Arc-length parametrization
For a regular curve, $s(t)=\int_{t_0}^t|\alpha'(r)|dr$ has positive derivative and hence a smooth inverse. Reparametrization by $s$ gives unit speed.
= Arc-length parametrization
For a regular curve, $s(t)=\int_{t_0}^t|\alpha'(r)|dr$ has positive derivative and hence a smooth inverse. Reparametrization by $s$ gives unit speed.