Given:
The degree of the polynomial f is 3.
the zeros are 9 and -5-i.
We know that the degree of the polynomial = the number of zeros of the polynomial.
The number of zeros of the polynomial =3.
We have two zeros, we need to find the one zero of the given polynomial.
Recall that the complex zeros are always in pairs.
The conjugate of -5-i is
[tex]-5+i[/tex]Hence the remaining zero of the polynomial is
[tex]-5+i[/tex]