Final answer:
Studying quadratic functions, rational functions, exponential functions, and polynomial equations is part of the Algebra branch of mathematics.
Step-by-step explanation:
When dealing with quadratic functions, rational functions, exponential functions, and polynomial equations, you are primarily studying the branch of mathematics known as Algebra. These functions and equations are fundamental to Algebra, which is a branch that deals with symbols and the rules for manipulating those symbols in formulas. Mathematical functions, such as quadratic functions, describe relationships and are essential in the construction of Algebraic models.