00:01
This question gives us a relation in the form of a table and asks us if it is a function or not.
00:07
We're given the x values 0, 1, and 2, and the y values 0, negative 1, and negative 2.
00:14
So what makes a relation a function? well, to be a function, every x value must map to 1 and only 1, y value.
00:24
So we can have, say, an x1 and an x2 both map to y, and that's fine because x, x1 maps to one and only one y value and x2 maps to one and only one y value but if we have an x that goes to y1 and to y2 then that's not all right because now we have two y values for this one x so the first and second examples are fine but the third example is not a function well let's take a look at the relation that we're given we see that each x value zero one and two has only one instance in this relation and it goes to one other y value, 0, negative 1, and negative 2.
01:08
Since there's no x values that have more than 1 y value, we can say for sure that this is a function.
01:17
So this relation is a function...