Relations and Functions, Domain & Range A RELATION is an equation which establishes the relationship between two variables and helps determine one variable when given the other. y = x2 y = -2x + 5 A relation is called a FUNCTION when there is no more than one output for each input. x=2 The set of possible inputs of a relation is called the DOMAIN, while the set of all possible outputs of a relation is called the RANGE. f(x)=3x+4 f(2)=10 Day 98

Functions A way to determine whether a relation is a function is to use the vertical line test. Use a pencil or a straightedge to represent a vertical line. Place the pencil at the left of the graph. Move it to the right across the graph. If, for each value of x in the domain, it passes through no more than one point on the graph, then the graph represents a function. Day 98

Functions Day 98