MathDB
Beautiful polynomial

Source: Serbia and Montenegro TST 2004 Problem 3

January 30, 2006
algebrapolynomialalgebra unsolved

Problem Statement

Let P(x)P(x) be a polynomial of degree nn whose roots are i1,i2,,ini-1, i-2,\cdot\cdot\cdot, i-n (where i2=1i^2=-1), and let R(x)R(x) and S(x)S(x) be the polynomials with real coefficients such that P(x)=R(x)+iS(x)P(x)=R(x)+iS(x). Show that the polynomial RR has nn real roots. (R. Stanojevic)