MathDB
Two quadratics

Source: All-Russian MO 2023 Final stage 9.1

April 23, 2023
quadraticsalgebra

Problem Statement

Given are two monic quadratics f(x),g(x)f(x), g(x) such that f,g,f+gf, g, f+g have two distinct real roots. Suppose that the difference of the roots of ff is equal to the difference of the roots of gg. Prove that the difference of the roots of f+gf+g is not bigger than the above common difference.