1. The so-called big-O notation is commonly used in computer science when analyzing the complexity of an algorithm. Wikipedia has a good discussion at https://en.wikipedia.org/wiki/Big_O_notation. There are multiple symbols used for slightly different characterizations of asymptotic complexity: O, o, Ω, ω, and Θ. Big-O is used most commonly, and indicates a worst-case behavior; Big-Theta indicates an asymptote for both worst case and best case; Big-Omega indicates a best-case behavior. Small-o and Small-omega are used to express the somewhat more complex concepts of one function dominating another rather than bounding another.