[2] **viXra:1802.0096 [pdf]**
*submitted on 2018-02-08 06:48:35*

**Authors:** Jesús Álvarez Lobo

**Comments:** 3 Pages. Spanish.

Solution to the problem PMO33.5. Problema del Duelo Matemático 08 (Olomouc – Chorzow - Graz).
Let a, b, c in ℝ. Prove that V = 4(a² + b² + c² ) - (a + b)² - (b + c)² - (c + a)² >= 0, and determine all values of a, b, c for which V = 0.

**Category:** Algebra

[1] **viXra:1802.0022 [pdf]**
*submitted on 2018-02-02 16:54:13*

**Authors:** Jesús Álvarez Lobo

**Comments:** 20 Pages.

The algorithm presented here is to be applied to polynomials whose independent term has many divisors. This type of polynomials can be hostile to the search for their integer roots, either because they do not
have them, or because the first tests performed have not been fortunate.
This algorithm was first published in Revista Escolar de la Olimpíada Iberoamericana de Matemática,
Number 19 (July - August 2005). ISSN – 1698-277X, in Spanish, with the title ALGORITMO DE DESCARTE DE RAÍCES ENTERAS DE POLINOMIOS.
When making this English translation 12 years later, some erratum has been corrected and when observing from the perspective of time that some passages were somewhat obscure, they have been rewritten trying to make them more intelligible.
The algorithm is based on three properties of divisibility of integer polynomials, which, astutely implemented, define a very compact systematic that can simplify significantly the exhaustive search of integer roots and rational roots.
Although there are many other methods for discarding roots, for example, those based on bounding rules, which sometimes drastically reduce the search interval, for the sake of simplicity, they will not be considered here.
The study presented here could be useful to almost all the young people of the planet, since at some stage of their academic training they will have to solve polynomial equations with integer coefficients, looking
for rational solutions, integer or fractional.
The author thinks that DARRIP's algorithm should be incorporated into the curricula of all the elementary study centers over the world.

**Category:** Algebra