Do Now: Solve the following: g(x) = 2x2 – 7 f(x) = 4x – 10 h(x) = 3 – 5x

We’ve been working with functions but what are they?? What is a Function?? We’ve been working with functions but what are they??

First….Relations A relation is information that can be represented by a set of ordered pairs (Room 615, Ms. Taylor’s Math Class) (Room 617, Mrs. Sawyer’s Math Class) (Room 628, Mr. Green’s Math Class)

Remember… A relation can have forms other than a coordinate pair: Mapping Table Graph

Functions A function is a relation in which each input (domain/x-value) is paired with exactly one output (range/y-value)

Think of your output number as a mailbox. A function is a relation in which each input (range/y-value) is paired with exactly one output (domain/x-value) To help remember & understand the definition: Think of your input number as a letter. Think of your output number as a mailbox.

A function is a relation in which each input (range/y-value) is paired with exactly one output (domain/x-value) Input number Output number Can you have one letter going to two different mail boxes? Not a FUNCTION

A function is a relation in which each input (range/y-value) is paired with exactly one output (domain/x-value) Input number Output number Can you have two different letters going to one mail box?

So Basically… If there is more than one of the same numbers in the domain….not a function!! CONNOT REPEAT THE X-VALUE However, we can have more than one of the same y-value

Is this a function? x y Yes, it is a Function 1 2 3 4 x y 5 6 7 5 6 7

Is this a Function? Not a Function x y x y 5 6 1 7 1 6 1 2 5 6 7

Is this a Function? Not a function x y 5 6 8 11 1 2 3 x y 5 6 11 8

Class Work Worksheet The answers are posted on the board! When done get out your Math Weekly #6 and work on it. If you finished it, have Ms. Taylor check it and help others…DO NOT LET THEM COPY, I WILL RIP YOUS AND THEIRS UP!