Defining explicit functions and recursive processes.
Mapped to CCSS Section# HSF.BF.A.1, HSF.BF.A.1a, HSF.IF.A.3
Write a function that describes a relationship between two quantities. Determine an explicit expression, a recursive process, or steps for calculation from a context. Recognize that sequences are functions, sometimes defined recursively, whose domain is a subset of the integers. For example, the Fibonacci sequence is defined recursively by f(0) = f(1) = 1, f(n+1) = f(n) + f(n-1) for n ≥ 1.