Category:Definitions/Maximum Value of Real Function

From ProofWiki
Jump to navigation Jump to search

This category contains definitions related to Maximum Value of Real Function.
Related results can be found in Category:Maximum Value of Real Function.


Absolute Maximum

Let $f: \R \to \R$ be a real function.

Let $f$ be bounded above by a supremum $B$.

It may or may not be the case that $\exists x \in \R: \map f x = B$.

If such a value exists, it is called the maximum of $f$ on $S$, and that this maximum is attained at $x$.


Local Maximum

Let $f$ be a real function defined on an open interval $\openint a b$.

Let $\xi \in \openint a b$.

Then $f$ has a local maximum at $\xi$ if and only if:

$\exists \openint c d \subseteq \openint a b: \forall x \in \openint c d: \map f x \le \map f \xi$

That is, if and only if there is some subinterval on which $f$ attains a maximum within that interval.