**Each input can match up to only one output Functions: Functions have EXACTLY ONE output for each input – **Each input can match up to only one output Examples: ATM Vending Machine Key – Lock Gas Station Calculator Remote Control Pencil Sharpener Phone Keyboard CD Player Oven

INPUT / OUTPUT INPUT: The value substituted into an expression or function OUTPUT: The value that results from the substitution of a given input into an expression or function.

*MAPPING* Function: Non-Function:

Mapping: “left” is the input, and “right” is the output Tia Shay Sam Joe Tom Swim Cheer Football Basketball Piano 6 12 18 18 36 54 4 8 12 15 Functions have EXACTLY ONE output for each input

Mapping: “left” is the input, and “right” is the output Not a Function: 18 has 2 outputs Tia Shay Sam Joe Tom Swim Cheer Football Basketball Piano 6 12 18 18 36 54 4 8 Function: each input has only 1 output 12 15 Not a Function: Tia and Tom have 2 outputs each Functions have EXACTLY ONE output for each input

*TABLES* Function: Non-Function:

“x” is the input, and “y” is the output. Tables: “x” is the input, and “y” is the output. For a table to represent a function, a number can show up in the x column only one time (input), but in the y column many times (output). x y 2 8 3 9 5 10 4 11 x y 1 3 2 10 4 Functions have EXACTLY ONE output for each input

*ORDERED PAIRS* Don’t forget that a relation has brackets { } on the outsides and parenthesis ( ) around each set. Function: Non-Function:

Ordered Pairs: “x” is the input, and “y” is the output {(-1, 1), (-2, -3), (-3, 3)} {(4, 2), (4, 5), (6, 8), (10,8)} Functions have EXACTLY ONE output for each input

Ordered Pairs: “x” is the input, and “y” is the output {(-1, 1), (-2, -3), (-3, 3)} {(4, 2), (4, 5), (6, 8), (10,8)} FUNCTION – none of the “x” values repeat RELATION – there are two 4’s in the “x” value Functions have EXACTLY ONE output for each input

Graphs: Vertical Line Test: **If you draw a straight line down through your graph, and it hits only once, then the graph is a function. If it hits more than once, then the graph is not a function, but a relation. Function: Non-Function:

Graphs: Vertical Line Test: **If you draw a straight line down through your graph, and it hits only once, then the graph is a function. If it hits more than once, then the graph is not a function, but a relation.

Vertical Line Test: **If you draw a straight line down through your graph, and it hits only once, then the graph is a function. If it hits more than once, then the graph is not a function, but a relation. Non - Function Function Function

Linear vs. Non Linear:

One output for each input Common difference / straight line RELATIONS (Sets of Data) FUNCTION One output for each input LINEAR Common difference / straight line NON - LINEAR

Only functions are linear. Linear or Non-Linear Only functions are linear. For a function to be linear, there has to be a common difference – this means to look at the outputs, and if you get the same solution when you subtract, you have a common difference. Linear functions, when graphed, form a straight line.

Graph: **It means formed by a line **These linear equations look like a line when graphed Linear Non-Linear

Table: To determine if a table has a linear relationship, look for a common difference (SLOPE). x 1 2 3 4 y 6 9 12 x 4 5 6 7 y 16 25 36 49 CD: CD:

Equation: If you want to check if an equation is linear, use the check list: NO exponents x3 No variables being multiplied together 6xy No variables in denominator 𝟑𝐱 𝐲 3 checks = LINEAR

Is it Linear?? *When looking at a graph, if it makes a straight line, IT’S LINEAR. *When looking at a table, if there is a common difference, IT’S LINEAR. *When looking at an equation, if there are no exponents, no variables multiplied together, and no variables in the denominator, IT’S LINEAR.

Ticket Out The Door… On your sticky note, write down if you think the following functions are LINEAR or NON - LINEAR

2a + 3b = 4 y = 5x – 3xy y = 1 x A = s2 *No Exponents *No variables being multiplied together *No variable in denominator

2a + 3b = 4 LINEAR y = 5x – 3xy NON - LINEAR y = 1 x A = s2