MathDB
Obtuse isosceles iff quadratic has distinct roots

Source: Canada Repêchage 2018/3

April 9, 2018
quadraticsgeometry

Problem Statement

Let ABCABC be a triangle with AB=BCAB = BC. Prove that △ABC\triangle ABC is an obtuse triangle if and only if the equation Ax2+Bx+C=0Ax^2 + Bx + C = 0 has two distinct real roots, where AA, BB, CC, are the angles in radians.
Back to ProblemsView on AoPS