MathDB
Putnam 2007 A2

Source:

December 3, 2007
Putnamgeometryconicshyperbolaanalytic geometryinequalitiesrectangle

Problem Statement

Find the least possible area of a convex set in the plane that intersects both branches of the hyperbola xy\equal{}1 and both branches of the hyperbola xy\equal{}\minus{}1. (A set S S in the plane is called convex if for any two points in S S the line segment connecting them is contained in S. S.)