Arturo O. answered 05/23/20
Experienced Physics Teacher for Physics Tutoring
The complex conjugate of a complex zero must also be a zero, so you will have 3 zeros:
3
4 + i
4 - i
f(x) = (x - 3) [x - (4 + i)] [x - (4 - i)]
You expand this to standard form. The coefficients will all come out real.