Subset in the coordinate plane - ILL 1990 KOR3
Source:
September 19, 2010
analytic geometrygeometryparallelogramvectorgeometric transformationhomothetyratio
Problem Statement
Let be a subset in the coordinate plane defined by , where is set of integers. Prove that for any parallelogram with center in the origin of coordinate and area , there exist at least two points of located in it.