MathDB
Parabolas

Source: IMC 2002 day 1 problem 1

October 7, 2005
conicsparabolaquadraticsalgebrapolynomialgeometrygeometric transformation

Problem Statement

A standard parabola is the graph of a quadratic polynomial y=x2+ax+by = x^2 + ax + b with leading co\"efficient 1. Three standard parabolas with vertices V1,V2,V3V1, V2, V3 intersect pairwise at points A1,A2,A3A1, A2, A3. Let As(A)A \mapsto s(A) be the reflection of the plane with respect to the xx-axis. Prove that standard parabolas with vertices s(A1),s(A2),s(A3)s (A1), s (A2), s (A3) intersect pairwise at the points s(V1),s(V2),s(V3)s (V1), s (V2), s (V3).