- 곡률,curvature . . . . 1 match
Def. $\kappa\ne 0$ 일 때, principal_unit_normal_vector(see [[단위법선벡터,unit_normal_vector]]) for a smooth curve in the plane is - 단위법선벡터,unit_normal_vector . . . . 1 match
Srch:principal_unit_normal_vector ? - chk. Google:principal+unit+normal+vector