It is sought to find a locus of a variable point having constant cross-ratio of a pencil of rays emanating from it and connecting to four fixed points in order to relate its cross-ratio to a conic property.
The Bulletin of Society for Mathematical Services and Standards (Volume 6)
G.L. Narasimham "Conjecturing Constant Cross-Ratio Loci of a Pencil in E2", The Bulletin of Society for Mathematical Services and Standards, Vol. 6, pp. 32-34, 2013