Manipulating Polynomials
Source: Tournament of Towns Sprin 2016
February 22, 2017
combinatoricsalgebrapolynomialinvariant
Problem Statement
On a blackboard, several polynomials of degree are written, each of them has the leading coefficient equal to . Initially all coefficients of each polynomial are non-negative. By one move it is allowed to erase any pair of polynomials and replace it by another pair of polynomials of degree with the leading coefficients equal to such that either or . Prove that it is impossible that after some move each polynomial
on the blackboard has distinct positive roots. (8 points)Alexandr Kuznetsov