Find an nth-degree polynomial function with real coefficients, a leading coefficient of 1, and satisfying the given conditions

Question

n = 3; 1 and 3i are zeros

Answer 1

-3i is also a zero.

(x-1)(x-3i)(x+3i) =

(x-1)(x^2 + 9) =

x^3 - x^2 + 9x - 9