Write a polynomial function of f lest degree that has rational coefficients a leading coefficient of 1 and the given zeros 5,-2i

Answer 1

Since -2i is a root, so is 2i.

f(x) = (x - 5)(x - 2i)(x - (-2i)) = (x - 5)(x - 2i)(x + 2i) = (x - 5)(x² + 4)