Consider the relation $R$ from set $A=\{1,2,3,4\}$ to set $B=\{2,4,6,8\}$ given by $R=\{(1,2),(2,4),(3,6),(4,8)\}$. Which of the following statements is correct?

Step-by-step solution

1. List the ordered pairs of $R$: each element of $A$ appears exactly once as a first coordinate.
2. Since every element of $A$ is related to exactly one element of $B$, $R$ satisfies the definition of a function.
3. Check whether any two different elements of $A$ have the same image in $B$. The images are 2, 4, 6, 8 – all distinct.
4. Hence the function is also one‑one (injective).

Concept tested: Testing a relation for being a function

Published 2 September 2026 · How this solution was prepared and checked

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