Sensitivity of the “intermediate point” in the mean value theorem: an approach via the Legendre-Fenchel transformation

We study the sensitivity, essentially the differentiability, of the so-called “intermediate point” c in the classical mean value theorem fa-f(b)b-a=f'(c)$ \frac{f(a)-f(b)}{b-a}={f}^{\prime}(c)$we provide the expression of its gradient ∇c(d,d), thus giving the asymptotic behavior of c(a, b) when...

Full description

Bibliographic Details
Main Author: Hiriart-Urruty Jean-Baptiste
Format: Article
Language:English
Published: EDP Sciences 2021-08-01
Series:ESAIM: Proceedings and Surveys
Online Access:https://www.esaim-proc.org/articles/proc/pdf/2021/02/proc2107110.pdf
id doaj-d342b9404c7b4777b0f63b6528b68b70
record_format Article
spelling doaj-d342b9404c7b4777b0f63b6528b68b702021-09-02T09:29:22ZengEDP SciencesESAIM: Proceedings and Surveys2267-30592021-08-017111412010.1051/proc/202171114proc2107110Sensitivity of the “intermediate point” in the mean value theorem: an approach via the Legendre-Fenchel transformationHiriart-Urruty Jean-Baptiste0Institut de Mathématiques, Université Paul SabatierWe study the sensitivity, essentially the differentiability, of the so-called “intermediate point” c in the classical mean value theorem fa-f(b)b-a=f'(c)$ \frac{f(a)-f(b)}{b-a}={f}^{\prime}(c)$we provide the expression of its gradient ∇c(d,d), thus giving the asymptotic behavior of c(a, b) when both a and b tend to the same point d. Under appropriate mild conditions on f, this result is “universal” in the sense that it does not depend on the point d or the function f. The key tool to get at this result turns out to be the Legendre-Fenchel transformation for convex functions.https://www.esaim-proc.org/articles/proc/pdf/2021/02/proc2107110.pdf
collection DOAJ
language English
format Article
sources DOAJ
author Hiriart-Urruty Jean-Baptiste
spellingShingle Hiriart-Urruty Jean-Baptiste
Sensitivity of the “intermediate point” in the mean value theorem: an approach via the Legendre-Fenchel transformation
ESAIM: Proceedings and Surveys
author_facet Hiriart-Urruty Jean-Baptiste
author_sort Hiriart-Urruty Jean-Baptiste
title Sensitivity of the “intermediate point” in the mean value theorem: an approach via the Legendre-Fenchel transformation
title_short Sensitivity of the “intermediate point” in the mean value theorem: an approach via the Legendre-Fenchel transformation
title_full Sensitivity of the “intermediate point” in the mean value theorem: an approach via the Legendre-Fenchel transformation
title_fullStr Sensitivity of the “intermediate point” in the mean value theorem: an approach via the Legendre-Fenchel transformation
title_full_unstemmed Sensitivity of the “intermediate point” in the mean value theorem: an approach via the Legendre-Fenchel transformation
title_sort sensitivity of the “intermediate point” in the mean value theorem: an approach via the legendre-fenchel transformation
publisher EDP Sciences
series ESAIM: Proceedings and Surveys
issn 2267-3059
publishDate 2021-08-01
description We study the sensitivity, essentially the differentiability, of the so-called “intermediate point” c in the classical mean value theorem fa-f(b)b-a=f'(c)$ \frac{f(a)-f(b)}{b-a}={f}^{\prime}(c)$we provide the expression of its gradient ∇c(d,d), thus giving the asymptotic behavior of c(a, b) when both a and b tend to the same point d. Under appropriate mild conditions on f, this result is “universal” in the sense that it does not depend on the point d or the function f. The key tool to get at this result turns out to be the Legendre-Fenchel transformation for convex functions.
url https://www.esaim-proc.org/articles/proc/pdf/2021/02/proc2107110.pdf
work_keys_str_mv AT hiriarturrutyjeanbaptiste sensitivityoftheintermediatepointinthemeanvaluetheoremanapproachviathelegendrefencheltransformation
_version_ 1721177143265722368