Answer:
domain: all real numbers
range: y ≥ -5
Step-by-step explanation:
The domain of any polynomial function is "all real numbers."
This polynomial is of even degree and has a positive leading coefficient. It will have a minimum value, but no maximum. We can get an idea of the minimum value by looking at the vertex form.
f(x) = x^4 -2x^2 -4
f(x) = (x^4 -2x^2 +1) -5 = (x^2 -1)^2 -5
The squared term will have a minimum value of 0, so the minimum of f(x) is -5.
The range is all real numbers greater than or equal to -5.
