\documentclass{minimal}
\usepackage{amsmath}
\usepackage{fontspec}
\usepackage{unicode-math}
\usepackage{graphicx}

\usepackage[
	papersize={145mm,105mm},
	layouthoffset=0mm,
	layoutvoffset=0mm,
	left = 0mm,
	right = 0mm,
	top = 1mm,
	bottom = 0mm,
]{geometry}

\setmainfont{LibertinusSerif-Regular.otf}
\setsansfont{LibertinusSans-Regular.otf}
\setmonofont{LibertinusMono-Regular.otf}
\setmathfont{LibertinusMath-Regular.otf}
\setmathfont{LibertinusMath-Regular.otf}

\def\sample#1#2#3{{\fontspec{#1} #3} & \scalebox{.6}[1]{\texttt{#2}}}
\def\panagram#1#2{\sample{#1}{#2}{The Quick Brown Fox Jumps Over The Lazy Dog}}

\begin{document}
\pagestyle{empty}

\begin{center}
  \begin{tabular}{l r}
   \panagram{LibertinusSerif-Regular.otf}        {Libertinus Serif} \\
   \panagram{LibertinusSerifDisplay-Regular.otf} {Libertinus Serif Display} \\
   \panagram{LibertinusSerif-Italic.otf}         {Libertinus Serif Italic} \\
   \panagram{LibertinusSerif-Semibold.otf}       {Libertinus Serif Semibold} \\
   \panagram{LibertinusSerif-SemiboldItalic.otf} {Libertinus Serif Semibold Italic} \\
   \panagram{LibertinusSerif-Bold.otf}           {Libertinus Serif Bold} \\
   \panagram{LibertinusSerif-BoldItalic.otf}     {Libertinus Serif Bold Italic} \\
   \panagram{LibertinusSans-Regular.otf}         {Libertinus Sans} \\
   \panagram{LibertinusSans-Italic.otf}          {Libertinus Sans Italic} \\
   \panagram{LibertinusSans-Bold.otf}            {Libertinus Sans Bold} \\
   \panagram{LibertinusMono-Regular.otf}         {Libertinus Mono} \\
   \sample{LibertinusSerifInitials-Regular.otf}  {Libertinus Serif Initials}{ABCDEFGHIJKLMOPQRSTUVWXYZ} \\
   \sample{LibertinusKeyboard-Regular.otf}       {Libertinus Keyboard}{Ctrl \textsf{+} Alt \textsf{+} F1 Enter} \\
  \end{tabular}
\end{center}

\begin{align*}
\left(x+α\right)^n	& =\sum_{k=0}^n \binom nk x^k α^{n-k}	\\
\left|x\right|		& =\begin{cases}
				-x,		& x<0	\\
				\phantom{-}x,	& x≥0	\\
			   \end{cases}				\\
	∇⋅∇ψ			& =\frac{∂^2ψ}{∂x^2}\mathbin{+}\frac{∂^2ψ}{∂y^2}+\frac{∂^2ψ}{∂z^2} \\
			& =\frac{1}{r^{2}\sin θ} \Bigg[\sin θ\frac{∂}{∂r}\bigg(r^{2}\frac{∂ψ}{∂r}\bigg)
			  +\frac{∂}{∂θ}\bigg(\sin θ\frac{∂ψ}{∂θ}\bigg)+\frac{1}{\sin θ}\frac{∂^{2}ψ}{∂φ^{2}}\Bigg]
\end{align*}
\end{document}
