Question 1083922
if only 1 value of y is pointed to by the same value of x, then you have a function.


if you also have only 1 value of x that points to the same value of y, then you have a 1 to 1 function.


if your re-orient your data in ascending values of x, you will get:


<pre>
     x     y
     -4     4
     -2     5
     -1     3
      0     2
      3    -3
      5     1
</pre>


you can see in this data that no 2 values of x are the same and no 2 values of y are the same.


therefore the data is a 1 to 1 function.


if it was not a function, you might have seen something like this:


<pre>
     x     y
     -2     4
     -2     5
     -1     3
      0     2
      3    -3
      5     1
</pre>


you can see that the -2 value of x points to more than one value of y.
that means it is not a function.


if it was a function, but not a 1 to 1 function, you might have seen something like this:


<pre>
     x     y
     -4     4
     -2     4
     -1     3
      0     2
      3    -3
      5     1
</pre>


you can see that the 4 value of y is pointed to by more than 1 value of x.
it is still a function because only one value of x points to the same value of y.
it is not a 1 to 1 function because more than 1 value of x points to the same value of y.


bottom line is that you have a 1 to 1 function.


here's a decent reference on the subject.


<a href = "http://www.purplemath.com/modules/fcns.htm" target = "_blank">http://www.purplemath.com/modules/fcns.htm</a>