# Bellringer 1. 2. 3..

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Bellringer

Relations and Functions Woohoo!!!
Chapter 5 Section 2 Relations and Functions Woohoo!!!

Some key terms Relation- a set of ordered pairs
Domain- the set of first coordinates, the x’s Range- the set of second coordinates, the y’s

Functions Function- a function is a relation in which each member of the domain is paired with exactly one member of the range In other words… you can not have a domain (x value) repeat itself Vertical Line Test- If any vertical line passes through no more than one point of the graph of a relation then the relation is a function

How to tell if it is a function
Since each element of the domain is paired with exactly one element of the range this is a function. Also, notice no x values are repeated

How to tell if it is a function
This is called a mapping. It shows the relation between each x and y value It does not matter that the y values are shared as long as the x value is not repeated or shared this is a function X 2 3 5 Y 3

Functional notation An equation looks like this
y = 3x + 5 This same equation written in functional notation looks like this f(x) = 3x + 5 We simply replace y with f(x)

Finding functional value
If f(x) = 2x +3 find each value. f(4) f(x) = 2x +3 f(4) = 2x +3 f(4) = 2(4) +3 f(4) = 8 +3 = 11 f(6a) f(x) = 2x +3 f(6a) = 2x +3 f(6a) = 2(6a) +3 f(6a) = 12a +3 = 12a +3

Your Turn If g(x) = 3x - 7 find each value. g(2h) 6h - 7 g(-2) -13

Assignment Page 244 #’s 1-33 odd