The population of an island is 6000 people this year and is projected to be 6300 people next year, if this trend has been going on for several years, when was the population 4000 people

Answer asap! show all work! find the number of complex roots, the possible number of real roots and the possible rational roots of the polynomial function. then, solve for all roots. x^3 + 2x^2 + 3x + 6 = 0