Question

Information is given about a polynomial f(x) whose coefficients are real numbers. Find the remaining zeros of f. Degree 3; zeros 9, -5-i

Answer 1

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

`-5+i`

Hence the remaining zero of the polynomial is

`-5+i`