
Arturo O. answered 07/12/20
Experienced Physics Teacher for Physics Tutoring
The complex conjugate of a complex zero must also be a zero, so you will have 4 zeros:
4i
-4i
3
-1
The polynomial is of degree 4.
f(x) = A(x - 4i)(x + 4i)(x - 3)(x + 1)
where A is a real integer and A ≠ 0.
f(x) = A(x2 + 16)(x - 3)(x + 1)
You can expand this to standard form if you wish.