# Help with a few questions?

## http://prntscr.com/jexvfp

May 7, 2018

Here's Help!

#### Explanation:

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: $\left({x}_{1} , {y}_{1}\right) \text{ and } \left({x}_{1} , {y}_{2}\right)$ 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 $\left(5 , 10\right)$, then it can't also be at 5 meters from the ground $\left(5 , 5\right)$ 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:

(-4,0)(-1,-3)(-3,5)(-1,1)

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!