Question

Identify the mapping diagram that represents the relation and determine whether the relation is a function. {(-6, -8), (2, -5), (1 ,-8), (3, 7)}

Answer 1

Keep in mind that x maps to y

For example, if you have (2,4), then you'll have a diagram where 2 maps to 4

Answer 2

A nice way of determining if it is a function for small finite pairs like this is to check if there are two pairs with the same x-value but different y-values.
If there is such a pair (or pairs), then your relation is not a function.
Otherwise, it is a function.

Please notify me if I made a mistake, thanks :)