SECTION 2-1: FUNCTIONS AND

THEIR GRAPHSGoal: Identify and graph

functions.

DEFINITIONS Relation: mapping or pairing, of input

values with output values.

Domain: Set of input values.

Range: set of output values.

Function: a relation is a function if each input value has exactly one output.

EXAMPLE 1: IDENTIFY FUNCTIONS

Identify the domain and range. Then tell whether the relation is a function. Explain.

CHECKPOINT: IDENTIFY FUNCTIONS

Identify the domain and range. Then tell whether the relation is a function. Explain.

EXAMPLE 2: APPLY THE VERTICAL LINE TEST Graph the relations from Ex. 1. Use the

vertical line test to tell whether the relation is a function.

CHECKPOINT: APPLY THE VERTICAL LINE TEST A. graph the relation shown in the diagram

below. B. Explain how to use the vertical line test to

show whether the relation is a function.

DEFINITIONS Equations in two variables: such as y = 5x

– 2; an ordered pair (x, y) is a solution of such an equation if substituting the values of x and y into the equation makes a true statement.

Independent variable: the input variable in an equation.

Dependent variable: the output variable.

EXAMPLE 3: GRAPH AN EQUATION Graph y = x + 1

CHECKPOINT: GRAPH AN EQUATION y = x - 3

CHECKPOINT: GRAPH AN EQUATION y = -x + 4

CHECKPOINT: GRAPH AN EQUATION y = 2x + 3

HOMEWORK:p. 70 – 72

14 – 46 even, 52-56