This math topic focuses on determining the domain of functions expressed as the ratio of a linear function to a quadratic function. It specifically deals with scenarios where the quadratic has complex roots. Students are required to choose which number line accurately represents the domain of these functions, enhancing their skills in understanding function behavior and identifying valid input values that do not lead to undefined expressions (such as division by zero in the case of these rational functions). Each question presents a function and multiple number line options as possible domains.