Help with a few questions?

1 Answer
May 7, 2018

Here's Help!


In order for a set of points to be a function, there must be only one #y# output for every #x# input . I could express it like this:

For a data set to be a proper function: #(x_1,y_1) " and " (x_1,y_2)# cannot exist.

Or think about it this way: If you were for example, graphing the path of a single ball through the air, if #x# is the amount to time passed, and #y# is the height of the ball in meters. If the ball is 10 meters from the ground after 5 seconds #(5,10)#, then it can't also be at 5 meters from the ground #(5,5)# after 5 seconds, because that ball can't exist in two different spots at once! Hope that makes sense.


The first question provides a table listing the points:


Within the points, #-4# has one #y# output, #-3#, has one output, but -1 has an output of #-3#. Therefore this is a relation.

The second question provides a mapping diagram. However, 6 maps to both 0 and 4 within the diagram, therefore that's a relation too. No relation can also be a function at the exact same time

And if that ball of yours exists at both 5 and 10 meters at the exact same time, well you just might want check it out...

Hope that helps!