Consider the set&nbsp;\(F = \{\text{Peter}, \text{John}, \text{Mark}\}\) and the set&nbsp;\(S = \{\text{Luke}, \text{Mary}, \text{Esther}\}\). In this scenario, it turns out that:
Luke and Mary are children of Mark. Esther is the daughter of Peter.
Let&nbsp;\(R\) be the relation between \(F\) and \(S\) that depicts the parent-child relation.
In general, \((p, c) \in R\) if and only if&nbsp;\(p\) is a parent of \(c\). We may sometimes write \(pRc\) in short for&nbsp;\((p, c) \in R\). We may also draw a diagram to show this relation \(R\).
From the given information, we can express:
\[R = \{(\text{Mark}, \text{Luke}), (\text{Mark}, \text{Mary}), (\text{Peter}, \text{Esther})\}\]
We can also draw a relation diagram to represent this relation \(R\):
<div class="content-block"><figure class="question-figure aligncenter" style="text-align: center;"><img src="https://vocwkpgapvksartxhhor.supabase.co/storage/v1/object/public/question-images/pasted/1770372337354-yn2ov5ut1rq.png" style="max-width: min(600px, 100%); height: auto; display: block;" alt="Relation diagram between sets F and S" class="aligncenter custom-width" /></figure></div>
Note that for a relation, it is not obliged that every element on the left is linked to some element on the right. It is also not required that a relation satisfies the condition that for every element on the left there is only \(1\) arrow emerging from it.

Consider the set \(F = \{\text{Peter}, \text{John}, \text{Mark}\}\) and the set \(S = \{\text{Luke}, \text{Mary}, \text{Esther}\}\). 
In this scenario, it turns out that:

Luke and Mary are children of Mark.  Esther is the daughter of Peter.

Let \(R\) be the relation between \(F\) and \(S\) that depicts the parent-child relation.

In general, \((p, c) \in R\) if and only if \(p\) is a parent of \(c\). We may sometimes write \(pRc\) in short for \((p, c) \in R\). 
We may also draw a diagram to show this relation \(R\).

From the given information, we can express:

\[R = \{(\text{Mark}, \text{Luke}), (\text{Mark}, \text{Mary}), (\text{Peter}, \text{Esther})\}\]

We can also draw a relation diagram to represent this relation \(R\):

Note that for a relation, it is not obliged that every element on the left is linked to some element on the right. It is also not required that a relation satisfies the condition that for every element on the left there is only \(1\) arrow emerging from it.

Functions

International Baccalaureate Higher Level Mathematics

Example of a relation

Example of a relation