MathDB
Maximum value of lambda

Source: Chinese MO 1999

March 19, 2012
algebrapolynomialinequalities proposedinequalities

Problem Statement

Determine the maximum value of λ\lambda such that if f(x)=x3+ax2+bx+cf(x) = x^3 +ax^2 +bx+c is a cubic polynomial with all its roots nonnegative, then f(x)λ(xa)3f(x)\geq\lambda(x -a)^3 for all x0x\geq0. Find the equality condition.