3.1 Relations and Functions

Vocab Relation: a set of ordered pairs Domain: All possible x values (inputs) Range: All possible y values (outputs) Function: a relation that has only ONE range for every domain

Functions? 1) Domain Range 2) Jorge 202 Domain Range Carolyn 142 Elaine 138 Saul This is a function. Each input has only one output. 2) Domain Range Cheese pizza $9.75 Tomato pizza $7.25 Meat pizza $8.50 This is not a function. The cheese pizza (input) has two outputs.

Functions? 3) (2, 4)(3, -12)(2, 9) (6, 3) Not a function because the domain of 2 has two different ranges. 4) (-1, 6) (5, 7)(9, 6) This is a function.

Functions? Try this… Domain Range A 4 B 0 C Yes this is a function. Each input only has one output.

Functions Try this again…. Domain Range P 0 Q 1 R 1 No this is not a function.

What is the domain and range of each function? Example 1: h: {(4, 0)(6, 0) (2,0)} Domain: {2, 4, 6} Range: {0} Example 2: j: {(1, 5)(3, 7)(1, 7)} Domain: {1, 3} Range: { 5, 7}

Domain and Range? Try this… 1.) {(Tom, 18)(Sue, 12)(Sue, 28)} Domain: { Tom, Sue} Range: {12, 18, 28} 2.) 3 36 7 35 6 Domain: {3, 6, 7} Range: {35, 36}

Function Notation f(x) is function notation, where x is your input and f(x) is your output. f(x) = x + 2, find f(8) f(8) = 8 + 2 f(8) = 10

Try this.. Find f(-2), f(0) and f(3) for f(x) = 2x + 1 f(-2) = -3