Arturo O. answered 05/24/20
Experienced Physics Teacher for Physics Tutoring
The complex conjugate of a complex zero must also be a zero, so you will have 4 zeros:
3
-2
-1 + i
-1 - i
f(x) = A (x - 3) (x + 2) [x - (-1 + i)] [ x - (-1 - i)]
The leading coefficient is A, which is given as 1, so
f(x) = (x - 3) (x + 2) [x - (-1 + i)] [ x - (-1 - i)]
If you expand this to standard form, all of the coefficients will come out real and rational.