This document discusses recurrences and the master method for solving recurrence relations. It defines a recurrence as an equation that describes a function in terms of its value on smaller functions. The master method provides three cases for solving recurrences of the form T(n) = aT(n/b) + f(n). If f(n) is asymptotically smaller than nlogba, the solution is Θ(nlogba). If f(n) is Θ(nlogba), the solution is Θ(nlogba lgn). If f(n) is asymptotically larger and the regularity condition holds, the solution is Θ(f(n)). It provides examples of applying