Inflection point of a plane cubic (source code)

= Inflection point of a plane cubic
{wiki=Inflection_point#Algebraic_geometry}

An inflection point of a smooth plane cubic is a point where its tangent line has intersection multiplicity three. Once one inflection point is chosen as the identity, the nine geometric inflection points are exactly the <torsion point of an elliptic curve>[3-torsion points].