This document discusses periodic functions and techniques for stretching, shrinking, and translating graphs of functions. It defines a periodic function as one where f(x+p)=f(x) for some period p and all x in the domain. The smallest such p is the fundamental period. Examples are given of finding the period and amplitude of functions from graphs, as well as stretching and shrinking graphs horizontally and vertically by multiplying or dividing the x-coordinates, and translating graphs by adding numbers to x or y.