是一個等倒點，如果對於曲線 
的每條弦 ![[x,y]](/images/equations/EquireciprocalPoint/Inline2.svg)
，
滿足
 |
等倒點
。 另請參閱
等弦點, 等積點使用 探索
參考文獻
Croft, H. T.; Falconer, K. J.; 和 Guy, R. K. Unsolved Problems in Geometry. New York: Springer-Verlag, p. 10, 1991.Falconer, K. J. "On the Equireciprocal Point Problem." Geom. Dedicata 14, 113-126, 1983.Hallstrom, A. P. "Equichordal and Equireciprocal Points." Bogasici Univ. J. Sci. 2, 83-88, 1974.Klee, V. "Can a Plane Convex Body have Two Equireciprocal Points?" Amer. Math. Monthly 76, 54-55, 1969.Klee, V. "Correction to 'Can a Plane Convex Body have Two Equireciprocal Points?' " Amer. Math. Monthly 78, 114, 1971.在 中被引用
等倒點請引用為
Weisstein, Eric W. "Equireciprocal Point." 來自 Web 資源。 https://mathworld.tw/EquireciprocalPoint.html