% % Copyright (C) 2018, 2019, 2020 by % Anna Capietto, Sandro Coriasco, Boris Doubrov, Alexander Koslovski, % Tiziana Armano, Nadir Murru, Dragan Ahmetovic, Cristian Bernareggi % % Based on accsupp and tagpdf % % This work consists of the main source files axessibility.dtx and axessibility.lua, % and the derived files % axessibility.ins, axessibility.sty, axessibility.pdf, README, % axessibilityExampleSingleLineT.tex, axessibilityExampleSingleLineA.tex, %. axessibilityExampleAlignT.tex, axessibilityExampleAlignA.tex % % This work may be distributed and/or modified under the % conditions of the LaTeX Project Public License, either version 1.3 % of this license or (at your option) any later version. % The latest version of this license is in % http://www.latex-project.org/lppl.txt % and version 1.3 or later is part of all distributions of LaTeX % version 2005/12/01 or later. % % This work has the LPPL maintenance status `maintained'. % % The Current Maintainer of this work is % Sandro Coriasco % \documentclass[a4paper,11pt]{article} \usepackage{axessibility} \title{The golden mean} \author{} \date{} \begin{document} \maketitle \tagstructbegin{tag=P} \tagmcbegin{tag=P} The golden mean is the number \tagmcend \tagstructend \[\frac{1 + \sqrt{5}}{2},\] \tagstructbegin{tag=P} \tagmcbegin{tag=P} that is, the root larger in modulus of \tagmcend \tagstructend \begin{equation} x^2 - x - 1. \end{equation} \tagstructbegin{tag=P} \tagmcbegin{tag=P} It is usually defined as the ratio of two lengths \auxiliaryspace \tagmcend \tagstructend \(a\) \tagstructbegin{tag=P} \tagmcbegin{tag=P} and \auxiliaryspace \tagmcend \tagstructend \(b\) \tagstructbegin{tag=P} \tagmcbegin{tag=P} such that \tagmcend \tagstructend \begin{equation*} (a+b) : a = a : b. \end{equation*} \tagstructbegin{tag=P} \tagmcbegin{tag=P} Let \auxiliaryspace \tagmcend \tagstructend \(x\) \tagstructbegin{tag=P} \tagmcbegin{tag=P} be the ratio \auxiliaryspace \tagmcend \tagstructend \( \frac{a}{b} \). \tagstructbegin{tag=P} \tagmcbegin{tag=P} We have \auxiliaryspace \tagmcend \tagstructend \( \frac{a+b}{a} = 1 + \frac{1}{x} \), \tagstructbegin{tag=P} \tagmcbegin{tag=P} from which we get the equation \auxiliaryspace \tagmcend \tagstructend \(x^2 = x + 1\). \end{document}