Bôcher notes that when P is the orthocenter, one obtains the nine-point circle, and when P is on the circumcircle of △ABC, then the conic is an equilateral hyperbola.
An approach to the nine-point hyperbola using the analytic geometry of split-complex numbers was devised by E. F. Allen in 1941.
, j2 = 1, he uses split-complex arithmetic to express a hyperbola as It is used as the circumconic of triangle
They requisitioned the unit circle in the complex plane as the circumcircle of the given triangle.
[2] For Yaglom, a hyperbola is a Minkowskian circle as in the Minkowski plane.
[3] He considers a triangle inscribed in a "circumcircle" which is in fact a hyperbola.
In the Minkowski plane the nine-point hyperbola is also described as a circle: In 2005 J.
Christopher Bath[5] describes a nine-point rectangular hyperbola passing through these centers: incenter X(1), the three excenters, the centroid X(2), the de Longchamps point X(20), and the three points obtained by extending the triangle medians to twice their cevian length.