Domain & Range---The Easy Way

First, let's start off with a little definition of each term so we can hopefully begin to understand these concepts a little better.

A function is a relation from a domain set to a range set, where each element of the domain set is related to exactly one element of the range set.

Domain-the set of all possible values of x.

Range-the set of all possible values of y.

               Y=X                          Y=|X|                        Y=X2-4                   Y=(X2-1)/(X+1)

                                              

Domain: 
(-infinity,infinity) 
 
Range: 

(-infinity,infinity)          

Domain

(-infinity,infinity)
 
Range

[0,infinity)         

                                          

Domain
(-infinity,infinity)
 
Range
[-4,infinity)              
Domain
-infinity,-1) U (1,infinity)
 
Range
(-infinity,-2)U(2,infinity)
 
 
 
            

The example graphs above demonstrate how the line relates to its domain and range. The domain and range are like boundaries and the line cannot go outside them.

The following is a short quiz about domain and range to test your knowledge of the concepts.