Functions What is a function? What are the different ways to represent a function?

Function A function is a mathematical “rule” that for each “input” (x-value) there is one and only one “output” (y – value). A function has a domain (input or x) and a range (output or y)

Examples of a Function 4 -2 1 8 -4 2 { (2,3) (4,6) (7,8)(-1,2)(0,4)}

Non – Examples of a Function 4 -2 1 8 -4 2 {(1,2) (1,3) (1,4) (2,3)} Vertical Line Test – if it passes through the graph more than once then it is NOT a function.

{(2,3) (2,4) (3,5) (4,1)} {(1,2) (-1,3) (5,3) (-2,4)} 4. 5. You Do: Is it a Function? Give the domain and range of each (whether it’s a function or not). {(2,3) (2,4) (3,5) (4,1)} {(1,2) (-1,3) (5,3) (-2,4)} 4. 5. -3 4 1 -5 9