Degree 4 => four roots (zeros).
Now, use the complex conjugate root theorem.
It states that if a polynomial with real coefficients has complex root a + bi then its complex conjugate a − bi is also a root of the polynomial.
The conjugate of i is - i and the conjugate of 14 + 1 is 14 - i, then it follows that those are the remaining zeros.
Answer: - i and 14 - i
