Namespaces
Variants
Actions

Difference between revisions of "Newton-Leibniz formula"

From Encyclopedia of Mathematics
Jump to: navigation, search
(TeX encoding is done + hyperlinks)
Line 1: Line 1:
The formula expressing the value of a definite integral of a given function <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/n/n066/n066550/n0665501.png" /> over an interval as the difference of the values at the end points of the interval of any primitive (cf. [[Integral calculus|Integral calculus]]) <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/n/n066/n066550/n0665502.png" /> of the function <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/n/n066/n066550/n0665503.png" />:
+
{{TEX|done}}
  
<table class="eq" style="width:100%;"> <tr><td valign="top" style="width:94%;text-align:center;"><img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/n/n066/n066550/n0665504.png" /></td> <td valign="top" style="width:5%;text-align:right;">(*)</td></tr></table>
+
The formula expressing the value of a definite integral of a given function $f$ over an interval as the difference of the values at the end points of the interval of any primitive (cf. [[Integral calculus|Integral calculus]])$F$ of the function $f$:
 +
\begin{equation}\label{eq:*}
 +
\int\limits_a^bf(x)\,dx = F(b)-F(a).
 +
\end{equation}
 +
It is named after I. Newton and G. Leibniz, who both knew the rule expressed by \ref{eq:*}, although it was published later.
  
It is named after I. Newton and G. Leibniz, who both knew the rule expressed by (*), although it was published later.
+
If $f$ is [[ Lebesgue integral | Lebesgue integrable]] over $[a,b]$ and $F$ is defined by
 
+
\begin{equation*}
If <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/n/n066/n066550/n0665505.png" /> is Lebesgue integrable over <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/n/n066/n066550/n0665506.png" /> and <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/n/n066/n066550/n0665507.png" /> is defined by
+
F(x) = \int\limits_a^xf(t)\,dt + C,
 
+
\end{equation*}
<table class="eq" style="width:100%;"> <tr><td valign="top" style="width:94%;text-align:center;"><img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/n/n066/n066550/n0665508.png" /></td> </tr></table>
+
where $C$ is a constant, then $F$ is [[Absolute_continuity#Absolute_continuity_of_a_function | absolutely continuous]], $F'(x) = f(x)$ almost-everywhere on $[a,b]$ (everywhere if $f$ is continuous on $[a,b]$) and \ref{eq:*} is valid.
 
 
where <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/n/n066/n066550/n0665509.png" /> is a constant, then <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/n/n066/n066550/n06655010.png" /> is absolutely continuous, <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/n/n066/n066550/n06655011.png" /> almost-everywhere on <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/n/n066/n066550/n06655012.png" /> (everywhere if <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/n/n066/n066550/n06655013.png" /> is continuous on <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/n/n066/n066550/n06655014.png" />) and (*) is valid.
 
  
 
A generalization of the Newton–Leibniz formula is the [[Stokes formula|Stokes formula]] for orientable manifolds with a boundary.
 
A generalization of the Newton–Leibniz formula is the [[Stokes formula|Stokes formula]] for orientable manifolds with a boundary.

Revision as of 08:22, 30 November 2012


The formula expressing the value of a definite integral of a given function $f$ over an interval as the difference of the values at the end points of the interval of any primitive (cf. Integral calculus)$F$ of the function $f$: \begin{equation}\label{eq:*} \int\limits_a^bf(x)\,dx = F(b)-F(a). \end{equation} It is named after I. Newton and G. Leibniz, who both knew the rule expressed by \ref{eq:*}, although it was published later.

If $f$ is Lebesgue integrable over $[a,b]$ and $F$ is defined by \begin{equation*} F(x) = \int\limits_a^xf(t)\,dt + C, \end{equation*} where $C$ is a constant, then $F$ is absolutely continuous, $F'(x) = f(x)$ almost-everywhere on $[a,b]$ (everywhere if $f$ is continuous on $[a,b]$) and \ref{eq:*} is valid.

A generalization of the Newton–Leibniz formula is the Stokes formula for orientable manifolds with a boundary.


Comments

The theorem expressed by the Newton–Leibniz formula is called the fundamental theorem of calculus, cf. e.g. [a1].

References

[a1] K.R. Stromberg, "Introduction to classical real analysis" , Wadsworth (1981) pp. 318ff
[a2] W. Rudin, "Real and complex analysis" , McGraw-Hill (1966) pp. 165ff
How to Cite This Entry:
Newton-Leibniz formula. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Newton-Leibniz_formula&oldid=28964
This article was adapted from an original article by L.D. Kudryavtsev (originator), which appeared in Encyclopedia of Mathematics - ISBN 1402006098. See original article