a. The domain of f consists of all x for which 3 – x > 0. Solving this inequality for x, we obtain x < 3. Thus, the domain of f is \{x \mid x<3\} or (-∞, 3). This is verified by the graph in Figure 3.14.

b. The domain of h consists of all x for which (x-3)^2>0. It follows that the domain of h is all real numbers except 3 . Thus, the domain of h is \{x \mid x \neq 3\} or (-∞, 3) \cup(3, \infty). This is shown by the graph in Figure 3.15. To make it more obvious that 3 is excluded from the domain, we used a DOT format.