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Viewing Version 6 of 'example of integration with respect to surface area of the paraboloid'
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Title of object: example of integration with respect to surface area of the paraboloid
Canonical Name: Example7OfIntegrationWithRespectToSurfaceArea
Type: Example

Created on: 2005-01-27 16:35:41
Modified on: 2005-10-15 15:39:23

Creator: yark
Modifier: yark
Author: yark
Author: rspuzio

Classification: msc:28A75

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

fixed, so accept correction

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:

\PMlinkescapeword{links}
\PMlinkescapeword{quick}

In this example, we examine the paraboloid given by the equation $z = x^2 + 3 y^2$. We have
$$\sqrt{1 + \left( \frac{\partial g}{\partial x} \right)^2 + \left( \frac{\partial g}{\partial y} \right)^2} =$$
$$\sqrt{1 + \left( 2 x \right)^2 + \left( 6 y \right)^2} = \sqrt{ 4 x^2 + 36 y^2 }$$
and, hence
$$\int_S f(x,y) \, d^2 A = \int f(x,y) \sqrt{ 4 x^2 + 36 y^2 } \, dx \, dy.$$

\PMlinkescapetext{\sl Quick links:}
\begin{itemize}
\item \PMlinkid{main entry}{6660}
\item \PMlinkid{previous example}{6669}
\item {next example}
\end{itemize}