I need an example of a continuous bijection $f:X \to Y$, where $X$ is NOT compact and $Y$ is Hausdorff, such that $f$ is not a homeomorphism. (It is easy to show that if $X$ is compact, then $f$ is necessarily a homeomorphism)
Any help is appreciated, Thanks !
$X=\mathbb{R}$ with discrete topology and $Y=\mathbb{R}$ with the usual topology, and $f=id$. $f$ is continuous bijective and $f^{-1}=id$ is not continuous.