The domain of the function f(x) = x^4 + 4x^2 + 4 is [0, inf). What is the range?

is this question right?? i keep getting (-inf, inf) when i try to find to domain of this.. ? so i don't even know how im supposed to find the range anymore

edit: i solved for it like a normal equation and i got x=sqrt2 i, -sqrt2 i.. is that supposed to help??

atlas9 Feb 2, 2020