MathDB
BMT 2014 Spring - Analysis P2

Source:

January 6, 2022
Polynomials

Problem Statement

Define η(f)\eta(f) to be the number of roots that are repeated of the complex-valued polynomial ff (e.g. η((x1)3(x+1)4)=5\eta((x-1)^3\cdot(x+1)^4)=5). Prove that for nonconstant, relatively prime f,gC[x]f,g\in\mathbb C[x], η(f)+η(g)+η(f+g)<degf+degg\eta(f)+\eta(g)+\eta(f+g)<\deg f+\deg g