 Constant functions: Functions that stay the same no matter what the variable does are called constant functions.
 Constants: are things that do not change: for example distance, volume, mass, are called constants. The things that do change are called variables
 Continuous graph: In a graph, a continuous line with no breaks in it forms a continuous graph
 Discontinuous graph: A line in a graph that is interrupted, or has breaks in it forms a discontinuous graph
 Function: A function f of a variable x is a rule that assigns to each number x in the function's domain a single number f(x). The word "single" in this definition is very important
graph A visual representation of data that displays the relationship among variables, usually cast along x and y axes.
 Relation: A relation is any pairing of a set of inputs with a set of outputs. Every function is a relation, but not every relation is a function. A relation is a function if for every input there is exactly one output.
 Mapping
 Input: The number or value that is entered, for example, into a function machine. The number that goes into the machine is the input
 Origin In the Cartesian coordinate plane, the origin is the point at which the horizontal and vertical axes intersect, at zero (0,0)
 Output: The number or value that comes out from a process. For example, in a function machine, a number goes in, something is done to it, and the resulting number is the output
 Domain
 Range
 Vertical line test: A relation represented by a graph is a function provided that no vertical line passes through more than one point on the graph.
 Test for Functions: Vertical Line test.
 Kinds of Mapping: one to one, many to one, onto, and into function.
 one to many and many to many are not functions.
 Type of Functions:
 Linear functions
 Linear functions
 Absolute Value functions
 Absolute Value Inequation functions
 Quadratic functions
 Rational functions
 Radical functions
 Inverse functions
 Exponential Functions
 Logarithmic functions
 Polynomial functions
 Trigonometric functions
