MathDB
A special polynomial condition

Source: Shortlist 2018 A6

July 17, 2019
algebrapolynomialIMO Shortlist

Problem Statement

Let m,n2m,n\geq 2 be integers. Let f(x1,,xn)f(x_1,\dots, x_n) be a polynomial with real coefficients such that f(x1,,xn)=x1++xnm for every x1,,xn{0,1,,m1}.f(x_1,\dots, x_n)=\left\lfloor \frac{x_1+\dots + x_n}{m} \right\rfloor\text{ for every } x_1,\dots, x_n\in \{0,1,\dots, m-1\}. Prove that the total degree of ff is at least nn.