Call a polynomial positive reducible if it can be written as a product of two nonconstant polynomials with positive real coefficients. Let f(x) be a polynomial with f(0)\not\equal{}0 such that f(xn) is positive reducible for some natural number n. Prove that f(x) itself is positive reducible. [L. Redei] algebrapolynomialsuperior algebrasuperior algebra unsolved