MathDB
Nice polynomial

Source: Iranian third round 2019 Finals Algebra exam problem 2

August 18, 2019
algebrapolynomial

Problem Statement

P(x)P(x) is a monoic polynomial with integer coefficients so that there exists monoic integer coefficients polynomials p1(x),p2(x),,pn(x)p_1(x),p_2(x),\dots ,p_n(x) so that for any natural number xx there exist an index jj and a natural number yy so that pj(y)=P(x)p_j(y)=P(x) and also deg(pj)deg(P)deg(p_j) \ge deg(P) for all jj.Show that there exist an index ii and an integer kk so that P(x)=pi(x+k)P(x)=p_i(x+k).