Source: /cirosantilli/maxima-and-minima

= Maxima and minima
{wiki}

Given a <function> $f$:
* from some space. For beginners the <real numbers> but more generally <topological spaces> should work in general
* to the <real numbers>
we want to find the points $x$ of the <domain (function)> of $f$ where the value of $f$ is smaller (for minima, or larger for maxima) than all other points in some <neighbourhood (mathematics)> of $x$.

In the case of <Functionals>, this problem is treated under the theory of the <calculus of variations>.