This math topic focuses on finding the domain of functions where the numerator is a square-rooted linear expression, and the denominator is a quadratic expression with complex roots. Students need to determine which number line represents the domains of these functions correctly. Each problem provides a function with specific constraints which must be analyzed to avoid the square root of a negative number and division by zero. Therefore, the skill of identifying allowable input values (the domain) for functions in given formats is practiced through multiple choice questions using number line visuals.