Let p(z) = z3 + (1 + j) z2 + (2 + j) z + 3, where z is a complex number.
Which one of the following is true?
1
All the roots cannot be real
2
conjugate {p(z)} = p(conjugate {z}) for all z
3
The sum of the roots of p(z) = 0 is a real number
4
The complex roots of the equation p(z) = 0 come in conjugate pairs