How do you know this is a function: (2,10) (4,1) (9,4) (3,2) (0,9)?
1 Answer
The given points all have different xcoordinates.
Explanation:
Recall that a function is a relationship where an inputted number gives only one output number. If there are two or more outputs for a given input, the relationship does not represent a function.
In your case, since each xcoordinate in the given points has only one ycoordinate, these points would represent a function.
However, if there was an added point that had an xcoordinate of any of the given points, the relationship would not represent a function since there would be two points with the
For example:

represents a function
#(1,5),(4,3),(3,2)# 
does not represent a function
#(color(red)1,color(green)5),(4,3),(color(red)1,color(green)7)#