Lecture 2 (Calculus) Functions, Graphing, Logarithms and Exponentials, and Function Composition

By the textbook definition, a function f : D → Y is a rule that:

1. A.Assigns each element of D to a unique element of Y
2. B.Assigns each element of Y to a unique element of D
3. C.Pairs every element of D with every element of Y
4. D.Matches elements of D and Y of equal magnitude