MATH

Function Function of single variable A relation f from a set $A$ to a set $B$ is said to be a function if every element of set $A$ has one and only one image in set $B$. In other words, a function $f$ is a relation such that no two pairs in the relation have the same first element. The notation $f : X \rightarrow Y$ means that $f$ is a function from $X$ to $Y$ . $X$ is called the domain of $f$, and $Y$ is called the co-domain of $f$. ...