We make the composition of both functions: f (x) = x ^ 2-1 g (x) = 2x-3 Then: f (g (x)) = (2x-3) ^ 2-1 Rewriting: f (g (x)) = 4x ^ 2-12x + 8 The domain of this function is all real numbers. Equivalently x: (-inf, inf) answer: x: (-inf, inf) option 1.