# Catalan surface

A ruled surface whose rectilinear generators are all parallel to the same plane. Its line of restriction (cf. Ruled surface) is planar. The position vector of a Catalan surface is $r=\rho(u)+vl(u)$, where $l''(u)\neq0$, $(l,l',l'')=0$. If all the generators of a Catalan surface intersect the same straight line, then the surface is a conoid.

#### References

 [1] E. Catalan, "Mémoire sur les surfaces gauches à plan directeur" , Paris (1843)

#### References

 [a1] W. Klingenberg, "A course in differential geometry" , Springer (1978) (Translated from German) [a2] R.S. Millman, G.D. Parker, "Elements of differential geometry" , Prentice-Hall (1977) pp. 31–35
How to Cite This Entry:
Catalan surface. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Catalan_surface&oldid=31979
This article was adapted from an original article by I.Kh. Sabitov (originator), which appeared in Encyclopedia of Mathematics - ISBN 1402006098. See original article