Question

If f(x) = x2 – 1 and g(x) = 2x – 3, what is the domain of (f o g)(x)

Answer 1

(f o g)(x) = f(g(x)) = (2x − 3)^2 − 1 = 4x^2 − 12x + 8. Both f and g are polynomials, so the domain is all real numbers: (-∞, ∞).