Question

look at this mapping diagram:
domain
-20
11
12
range
3
11
18
5
is this relation a function?
yes no

Explanation:

Step1: Recall the definition of a function

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

Step2: Analyze the domain elements

• The domain element -20: Let's check its mappings. From the diagram, -20 is mapped to some elements, but wait, no—wait, the domain has -20, 11, 12. Wait, the element 11 in the domain: how many range elements is it mapped to? Looking at the diagram, 11 is connected to multiple range elements (since there are multiple arrows from 11).
• By the definition of a function, if any domain element is paired with more than one range element, it's not a function. Here, 11 (in domain) is mapped to more than one range value (since there are multiple arrows from 11), so it violates the function definition.

Answer:

no