Students will learn how to identify the domain of a rational function. They'll start with rational functions where the denominator is linear. Next, students will consider functions where the denominator is quadratic. Finally, students will solve problems where the denominator is a radical expression. In any case, the problem can be solved by considering the denominator as a function, then finding its roots. This topic builds off not only the ability to solve linear and quadratic equations, but also, the understanding that division by zero is undefined.