The function $f(x) = 9x + 3$ is one-to-one.
(a) Find the inverse of $f$ and check the answer.
(b) Find the domain and the range of $f$ and $f^{-1}$.
(a) $f^{-1}(x) = \boxed{}$
(Simplify your answer. Use integers or fractions for any numbers in the expression.)
(b) Find the domain of $f$. Select the correct choice below and, if necessary, fill in the answer box to complete your choice.
A. The domain is $\{x|x \ne \boxed{ }\}$.
B. The domain is $\{x|x \le \boxed{ }\}$.
C. The domain is $\{x|x \ge \boxed{ }\}$.
D. The domain is the set of all real numbers.
Find the range of $f$. Select the correct choice below and, if necessary, fill in the answer box to complete your choice.
A. The range is $\{y|y \ge \boxed{ }\}$.
B. The range is $\{y|y \ne \boxed{ }\}$.