MathDB
Putnam 1999 A2

Source:

December 22, 2012
Putnamalgebrapolynomialcollege contests

Problem Statement

Let p(x)p(x) be a polynomial that is nonnegative for all real xx. Prove that for some kk, there are polynomials f1(x),f2(x),,fk(x)f_1(x),f_2(x),\ldots,f_k(x) such that p(x)=j=1k(fj(x))2.p(x)=\sum_{j=1}^k(f_j(x))^2.