%% 
%%  An UIT Edition example
%% 
%%  Example 09-06-2 on page 171.
%% 
%%  Copyright (C) 2010 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[]{exaarticle}
\pagestyle{empty}
\setlength\textwidth{375.57637pt}
\AtBeginDocument{\setlength\parindent{0pt}}
\StartShownPreambleCommands
\usepackage{bm,amsmath}
\DeclareBoldMathCommand[bold]{\Sin}{\mathrm{sin}}
\DeclareBoldMathCommand[bold]{\Alpha}{\alpha}
\StopShownPreambleCommands
\begin{document}
$ f(x)=\sin(x) $ $ \mathbf{f(x)=\sin(x)} $ $ \bm{f(x)=\sin(x)} $ \\
$ f(x)=\Sin(x) $ $ \mathbf{f(x)=\Sin(x)} $ $ \bm{f(x)=\Sin(x)} $ \\
$ f(\Alpha)=\Sin(\Alpha)$ $\mathbf{f(\Alpha)=\Sin(\Alpha)}$
                          $\bm{f(\Alpha)=\Sin(\Alpha)}$
\end{document}