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 10 of 'condition of orthogonality'
[ view 'condition of orthogonality' | back to history ]

Title of object: condition of orthogonality
Canonical Name: ConditionOfOrthogonality
Type: Result

Created on: 2004-11-07 10:06:03
Modified on: 2005-02-19 12:28:08

Creator: pahio
Modifier: pahio
Author: drini
Author: pahio

Classification: msc:15A57, msc:51F20
Keywords: straight line, slope
Defines: opposite inverse
Synonyms: condition of orthogonality=condition of perpendicularity

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}
\usepackage{graphicx}
Content:

Let two straight lines of the $xy$-plane have the slopes $m_1$ and $m_2$. \,The lines are at right angles to each other iff $m_1$ and $m_2$ are the {\em opposite inverses} of each other, i.e. \PMlinkname{iff}{Biconditional}
\[m_1m_2 = -1.\]

\textbf{Example.} \,The lines \,$y = (1+\sqrt{2})x$\, and \,$y = (1-\sqrt{2})x$\, are at right angles to each other.
\begin{center}
\includegraphics{orthogon}
\end{center}