Given that (+-2) and i are the roots of a 4th degree polynomical, find the equation.

Question

Please help! Thank you:)

Answer 1

complex roots come in pair, so -i is also a root

f(x) = (x-2)(x+2)(x-i)x+i)
= (x^2-4)(x^2+1)
= x^4 - 3x^2 - 4

Answer 2

Thanks!