MathDB
combinatorial geometry

Source: Netherlands TST for IMO 2017 day 3 problem 4

February 1, 2018
combinatoricsgeometry

Problem Statement

Let n2n \geq 2 be an integer. Find the smallest positive integer mm for which the following holds: given nn points in the plane, no three on a line, there are mm lines such that no line passes through any of the given points, and for all points XYX \neq Y there is a line with respect to which XX and YY lie on opposite sides