TOPICS
Search

Hofstadter Point


The r-Hofstadter triangle of a given triangle DeltaABC is perspective to DeltaABC, and the perspector is called the Hofstadter point. The triangle center function is

 alpha=(sin(rA))/(sin(r-rA)).
(1)

As r->0, the triangle center function approaches

 alpha_(360)=A/a,
(2)

which is Kimberling center X_(360), and as r->1, the triangle center function approaches

 alpha_(359)=a/A,
(3)

which is Kimberling center X_(359). X_(359) and X_(360) are examples of transcendental triangle centers, since they have no trilinear or barycentric representation using only algebraic functions of a, b, and c.


See also

Hofstadter Triangle

Explore with Wolfram|Alpha

References

Kimberling, C. "Hofstadter Points." Nieuw Arch. Wisk. 12, 109-114, 1994.Kimberling, C. "Major Centers of Triangles." Amer. Math. Monthly 104, 431-438, 1997.Kimberling, C. "Hofstadter Points." http://faculty.evansville.edu/ck6/tcenters/recent/hofstad.html.

Referenced on Wolfram|Alpha

Hofstadter Point

Cite this as:

Weisstein, Eric W. "Hofstadter Point." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/HofstadterPoint.html

Subject classifications