# Flecnode

From Encyclopedia of Mathematics

*on a planar curve*

A point at which a node (or double point; cf. also Node) and an inflection (cf. also Point of inflection) coincide.

Thus, one of the tangents at the node has intersection multiplicity at least $4$ with the curve at that point.

#### References

[a1] | J.W. Bruce, "Lines, surfaces and duality" Math. Proc. Cambridge Philos. Soc. , 112 (1992) pp. 53–61 |

[a2] | M. Tsuboko, "On the line complex determinant of flecnode tangents of a ruled surface and its flecnodal surfaces" Memoirs Ryojun Coll. Engin. , 11 (1938) pp. 233–238 |

**How to Cite This Entry:**

Flecnode.

*Encyclopedia of Mathematics.*URL: http://encyclopediaofmath.org/index.php?title=Flecnode&oldid=35930

This article was adapted from an original article by M. Hazewinkel (originator), which appeared in Encyclopedia of Mathematics - ISBN 1402006098. See original article