PlanetMath (more info)
 Math for the people, by the people. Sponsor PlanetMath
Encyclopedia | Requests | Forums | Docs | Wiki | Random | RSS  
Login
create new user
name:
pass:
forget your password?
Main Menu
Viewing Version 4 of 'Cauchy-Riemann equations (polar coordinates)'
[ view 'Cauchy-Riemann equations (polar coordinates)' | back to history ]

Title of object: Cauchy-Riemann equations (polar coordinates)
Canonical Name: CauchyRiemannEquationsPolarCoordinates
Type: Definition

Created on: 2003-11-15 12:05:14
Modified on: 2003-11-16 16:08:38

Creator: Daume
Modifier: Daume
Author: Daume

Classification: msc:30E99

Revision comment (for changes between this and next version):

Changes for correction #7188 ('attach').

Preamble:

% this is the default PlanetMath preamble. as your knowledge
% of TeX increases, you will probably want to edit this, but
% it should be fine as is for beginners.

% almost certainly you want these
\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{amsfonts}

% used for TeXing text within eps files
%\usepackage{psfrag}
% need this for including graphics (\includegraphics)
%\usepackage{graphicx}
% for neatly defining theorems and propositions
%\usepackage{amsthm}
% making logically defined graphics
%\usepackage{xypic}

% there are many more packages, add them here as you need them

% define commands here
Content:

Suppose $A$ is an open set in $\mathbb{C}$ and $f(z)=f(re^{i\theta})=u(r,\theta)+iv(r,\theta): A\subset\mathbb{C} \to \mathbb{C}$ is a function. If the derivative of $f(z)$ exists at $z_0=(r_0,\theta_0)$. Then the functions $u$, $v$ at $z_0$ satisfy:
\begin{eqnarray*}
\frac{\partial u}{\partial r} & = & \frac{1}{r}\frac{\partial v}{\partial \theta}\\
\frac{\partial v}{\partial r} & = & -\frac{1}{r}\frac{\partial u}{\partial \theta}
\end{eqnarray*}
which are called \emph{Cauchy-Riemann equations} in polar form.\\\\