2-1 Relations and Functions Big Idea: -Determine if a set of values is a relation. -Determine if a relation is a function.

Vocabulary Relation: a set of pairs of input and output values. (x, y)

Ex 1: Graph each relation {(0,2), (1, 3), (2, 4)}

B) {(-½, 3), (-4, -1), (5, 0)}

Domain: of a relation is a set of all inputs, or the x-coordinates of the ordered pairs. Range: of a relation is the set of all outputs, or y-coordinates of the ordered pairs.

Ex 2: Write the ordered pairs for each relation Ex 2: Write the ordered pairs for each relation. Find the domain and range. A( , ) B( , ) C( , ) D( , ) E( , ) F( , ) Domain: Range:

Making a mapping diagram A way of showing a relation that links the domain to the range. (x to y)

Ex 3: Make a mapping diagram for each relation. B) {(10, -5), (-4, 1), (0, 0), (4, -5)}

Function: a relation in which each element of the domain is paired with exactly one element in the range. y x

Ex 4: Determine whether each relation is a function. B) {(0, 5), (11, -7), (10,5)} C) {(2, 6), (6, 2), (0,0), (-2, 12)}

Ex 5: Use the vertical-line test to determine whether the graph represents a function. A) B)

C) D)

Ex 6: For each function, find f(-2), f(½), f(3). A) f(a) = 3a + 9 B) f(x) = -2x + ½