%%
%%  Ein Beispiel der DANTE-Edition
%%  Mathematiksatz mit LaTeX
%%  3. Auflage
%%  Beispiel 09-06-1 auf Seite 177.
%%  Copyright (C) 2018 Herbert Voss
%%
%%  It 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.
%%  See http://www.latex-project.org/lppl.txt for details.
%%
%% ====
% Show page(s) 1
%%
%%
\documentclass[10pt]{exaartplain}
\pagestyle{empty}
\setlength\textwidth{218.40707pt}
\AtBeginDocument{\setlength\parindent{0pt}}
%StartShownPreambleCommands
\usepackage{autobreak}
\newcommand\LR[1]{\left(#1\right)}
%StopShownPreambleCommands
\begin{document}
\begin{align} \everyafterautobreak{\cdot}
\begin{autobreak}
\cos\LR{\frac{\pi}{2}x}=
 \LR{1-x^2}\LR{1-\frac{x^2}{9}}
 \LR{1-\frac{x^2}{25}}\LR{1-\frac{x^2}{49}}
 \LR{1-\frac{x^2}{81}}\LR{1-\frac{x^2}{121}}
 \LR{1-\frac{x^2}{169}}\LR{1-\frac{x^2}{225}}
 \LR{1-\frac{x^2}{289}}\LR{1-\frac{x^2}{361}}
 \LR{1-\frac{x^2}{441}}\dots
\end{autobreak}
\end{align}
\end{document}