% % Copyright (C) 2018 by % Anna Capietto, Sandro Coriasco, Tiziana Armano, % Nadir Murru, Alice Ruighi, Eugenia Taranto, % Dragan Ahmetovic, Cristian Bernareggi, Michele Berra % % Based on accsupp.sty % % This work consists of the main source file axessibility.dtx % and the derived files % axessibility.ins, axessibility.sty, axessibility.pdf, README, % axessibilityExampleGoldenMean.tex % % The Current Maintainer of this work is % Sandro Coriasco % % This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 License % http://creativecommons.org/licenses/by-nc/4.0/ % \documentclass[a4paper,11pt]{article} \usepackage{axessibility} \title{The golden mean} \author{} \date{} \begin{document} \maketitle The golden mean is the number \[\frac{1 + \sqrt{5}}{2},\] that is the root larger in modulus of \begin{equation} x^2 - x - 1. \end{equation} It is usually defined as the ratio of two lengths \(a\) and \(b\) such that \begin{equation*} (a+b) : a = a : b. \end{equation*} Let \(x\) be the ratio \( \frac{a}{b} \), we have \( \frac{a+b}{a} = 1 + \frac{1}{x} \), from which we get the equation \(x^2 = x + 1\). \end{document}