%%
%% The LaTeX Companion, 3ed
%%
%% Example 12-4-5 on page II-259 in "Setting up Unicode math fonts".
%%
%% Copyright (C) 2022 Frank Mittelbach
%%
%% It may be distributed and/or modified under the conditions
%% of the LaTeX Project Public License, either version 1.3c
%% of this license or (at your option) any later version.
%%
%% See https://www.latex-project.org/lppl.txt for details.
%%

\documentclass{tlc3exa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{177.0pt}
% typeset with lualatex
%StartShownPreambleCommands
\usepackage{fontspec}     \setmainfont{Fira Sans}
\usepackage{unicode-math} \setmathfont{Fira Math}
%StopShownPreambleCommands

\begin{document}
An example showing a trigonometric function:
\[ \sin \frac{\alpha}{2} =
      \pm \sqrt{\frac{1-\cos\alpha}{2}} \]
Scripts: $A \neq \symbb{A} $; no other math
alphabets are available in Fira Sans.
\end{document}