MathDB
Non-zero coeficients

Source: Brazilian Olympic Revenge 2020, P1

February 1, 2020
olympic revengeBrazilalgebra

Problem Statement

Let nn be a positive integer and a1,a2,,ana_1, a_2, \dots, a_n non-zero real numbers. What is the least number of non-zero coefficients that the polynomial P(x)=(xa1)(xa2)(xan)P(x) = (x - a_1)(x - a_2)\cdots(x - a_n) can have?