Answer:
i, -i , 2i, -2i
Step-by-step explanation:
We can factor this as follows:-
x^4 + 3x^2 + 2 = 0
(x^2 + 1)(x^2 + 2) = 0
By the zero product postulate:-
x^2 + 1 = 0 or x^2 + 2 = 0
x^2 + 1 = 0
x = +/- √-1 = i , -i
x^2 + 2 = 0
x = +/- √-2 = 2 √-1 , -2√-1 = 2i; -2i.