Question

look at this mapping diagram
domain
11
15
18
range
7
-2
-10
is this relation a function?
yes no

Explanation:

Step1: Recall function definition

A function is a relation where each element in the domain is paired with exactly one element in the range.

Step2: Analyze domain elements

Check each domain element (11, 15, 18). Each has only one arrow to the range (so each domain element maps to one range element).

Answer:

yes