This document discusses polynomial and rational functions. A polynomial function of degree n can be written as p(x) = anxn + an-1xn-1 + ... + a1x + a0, where the coefficients a0, a1, ..., an are real numbers and an ≠ 0. A rational function is defined as f(x) = p(x)/q(x), where p(x) and q(x) are polynomial functions and q(x) ≠ 0. Several examples are provided of using rational functions to model real-world situations involving distance-time, concentration of a drug over time, and allocating a budget amount per child based on the total number of children.