# Lituus

From Encyclopedia of Mathematics

A plane transcendental curve whose equation in polar coordinates is

Figure: l059750a

To every value of correspond two values of , one positive and one negative. The curve consists of two branches, that both approach the pole asymptotically (see Fig.). The line is an asymptote at , and and are points of inflection. The lituus is related to the so-called algebraic spirals.

#### References

[1] | A.A. Savelov, "Planar curves" , Moscow (1960) (In Russian) |

#### Comments

#### References

[a1] | K. Fladt, "Analytische Geometrie spezieller ebener Kurven" , Akad. Verlagsgesell. (1962) |

[a2] | F. Gomes Teixeira, "Traité des courbes" , 1–3 , Chelsea, reprint (1971) |

**How to Cite This Entry:**

Lituus.

*Encyclopedia of Mathematics.*URL: http://encyclopediaofmath.org/index.php?title=Lituus&oldid=18088

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