Tom K. answered 11/07/20
Knowledgeable and Friendly Math and Statistics Tutor
If a root is complex, then its complex conjugate must be a root. If a square root is a root, so is its square root conjugate.
Thus, we have -i, i, √6, -√6 as roots.
Then, our polynomial is (x + i)(x - i)(x - √6)(x + √6) = (x2 + 1)(x2 - 6) or x4 -5x2 - 6