In mathematics, relations are a representation of the ‘relationship’ between two sets of numbers, usually showing a relationship between x and y.
Relations have more than one y-value.
Examples:
The price of a smartphone depends of how old the model is
Walking time depends of how long is the distance to a place
Relations can be represented in 6 different ways:
In words:
“The price of a watermelon (P) is related to its weight (W)”
Table of values:
Set of ordered pairs:
Mapping (arrow) diagram:
Equations:
Equations are usually relations when they have a square root (√) or squared ()
Graphs:
*Function notation is used to represent functions, a type of relation*
Functions are special relations, for a relation to be a function each input MUST only have ONE output (only one y-value (output) per one x-value (input)).
Functions can be represented in 7 different ways:
In words:
“Mrs. Smith has one son named James, and Mr. Campbell has one daughter named Lucy”
Table of values:
Set of ordered pairs:
Mapping (arrow) diagram:
Equations:
Graphs:
Function notation:
That is how functions and relations represented, remember that the difference between functions and relations is that relations have multiple y-values for one x-value, and a function only have one y-value for each x-value.






















