A. Definitions

Relation – a set of ordered pairs ie. {(1,2), (3,4), (5,6)}

Domain – the xvalues of the relation. (1,3,5)

Range – the yvalues of the relation. (2,4,6)
B. Identifying Relations that are Functions
 A relation is a function if no ordered pair has the same xvalue.
 The graph of a relation is a function if a vertical line touches the graph at only one point, as the vertical line passes over the graph. (Vertical Line Test)


C. Evaluating a Function (that’s in equation form) **f(x) replaces y and is read "f of x"
 Substitute the given xvalue in for x.
 Simplify by using order of operations.


