# Let X={1,2,3} and Y={4,5}.Find whether the following subsets of X x Y are functions from X to Y or not.$(iv)\quad k=\{(1,4),(2,5)\}$

Note: This is part 4 of a 4 part question, split as 4 separate questions here.

Toolbox:
• The given set of ordered pair subset of $x \times y$ function if same element $a \in x$ is not mapped on to two different elements of y
• The subset of $x \times$ is a function if it defines a mapping for each element of x an element of y
(iv) $k=\{(1,4),(2,5)\}$

Since $3 \in X$ does not have a mapping in the subset of $x \times y$ given by k

k is not a function