$f:Z \rightarrow Z$
$f(x) = x-5$ , when $x$ is odd
$f(x) = x+3$ , when $x$ is even
It seems that it is not onto, because not all integers are covered, but how do you show this?
$f:Z \rightarrow Z$
$f(x) = x-5$ , when $x$ is odd
$f(x) = x+3$ , when $x$ is even
It seems that it is not onto, because not all integers are covered, but how do you show this?