Can some explain this to me

Question

Find the domain and range of the following relation. Determine if the relation is a function and explain:
{(1,2), (3,3), (4,2), (5,6), (6,3)}

Answer 1

In order for it to be a function, that means that there cannot be any two repeating x values. If there are two repeating x values, that means a vertical line on the graph, which is undefined. Each set in parentheses is a data point where the x value is listed first and then the y value. So, for example, (1,2) means x = 1 and y = 2 on the graph. 

 

This is a function because none of the first numbers in each parentheses are the same

 

Also the domain (which is all of the x values) is {1, 3, 4, 5, 6)

The range (which is all of the y values) is {2, 3, 2, 6, 3)