You must do in this case is composition of both functions: a (x) = 3x + 1 b (x) = root (x-4) Making the composition b (a (x)) = root ((3x + 1) -4) Rewriting: b (a (x)) = root (3x-3) b (a (x)) = root (3 (x-1)) Answer: The domain of the function is: x> = 1 Equivalently: [1, inf)
