MathDB
IMC 2017 Problem 5

Source:

August 2, 2017
imc 2017IMCpolynomialcomplex analysis

Problem Statement

Let kk and nn be positive integers with nk23k+4n\geq k^2-3k+4, and let f(z)=zn1+cn2zn2++c0f(z)=z^{n-1}+c_{n-2}z^{n-2}+\dots+c_0 be a polynomial with complex coefficients such that c0cn2=c1cn3==cn2c0=0c_0c_{n-2}=c_1c_{n-3}=\dots=c_{n-2}c_0=0 Prove that f(z)f(z) and zn1z^n-1 have at most nkn-k common roots.