Sunday, March 19, 2023

1935. Collinear Points

1 comment:

  1. I think solution is trivial. Consider the two set of lines {ta,tb,tc} and {la,lb,lc}. These lines have 3.3=9 intersection points. These points define a cubic cıurve. Sir Angel Montesdeoca proved (https://amontes.webs.ull.es/otrashtm/HGT2019.htm#HG101119) that points other than ta ∩ la., tb ∩ lb., tc ∩ lc. lie on a conic. So These points lie on a line. On other words for P on Q136, cubic curve degenerates to a conic and a line.

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