# Poster and (very) bold math fonts

I've spent several hours to put some mathematical laws for powers and logarithm on a poster.

The output is too thin for reading it standing a few meters away, especially sitting in a classroom in the last row.

I have to use a bold font for math, but I don't find any solution.

\documentclass[final]{beamer} % beamer 3.10: do NOT use option hyperref={pdfpagelabels=false} !
\mode<presentation> {
\usetheme{default}
}
\usepackage[english]{babel}
\usepackage[latin1]{inputenc}
\usepackage{amsmath,amsthm, amssymb, latexsym}
%\usepackage{times}\usefonttheme{professionalfonts}  % times is obsolete
\usefonttheme[onlymath]{serif}
\boldmath
\usepackage[orientation=portrait,size=a1,scale=2.4,debug]{beamerposter}                       % e.g. for DIN-A0 poster
\title[]{Potenz- und Logarithmengesetze}
\begin{document}
\begin{frame}{}
\vfill
\begin{block}{\Huge\hspace{2cm} Potenzgesetze}
$\def\arraystretch{2}\begin{array}{rclp{5cm}} a^m \cdot a^m & = &a^{m+n} &\\ \displaystyle \frac{a^m}{a^n} & =& a^{m-n} \\ (a \cdot b)^m & =& a^m \cdot b^m \\ \displaystyle \left(\frac{a}{b}\right)^m & = & \displaystyle \frac{a^m}{b^m} \\ \bigl( a^m \bigr)^n & =& a^{m \cdot n} \\ \end{array}$
\end{block}
\vfill
\begin{block}{\Huge\hspace{2cm} Logarithmengesetze}
$\def\arraystretch{2}\begin{array}{rcl} \ln(a \cdot b) & = &\ln(a) + \ln(b) \\ \displaystyle \ln\left( \frac{a}{b} \right) & = &\ln(a) - \ln(b) \\ \ln(a^b) & =& b \cdot \ln(a) \\ \ln(e) & = &1 \\ \ln(1) & = &0 \\ \ln(e^x) & = &e^{\ln(x)} = x \end{array}$
\end{block}
\vfill
\end{frame}
\end{document}


That is one of my attemps. No luck.

Any help is appreciated!

• Welcome to TeX.SX! You can have a look at our starter guide to familiarize yourself further with our format. – karlkoeller Dec 6 '14 at 11:38

## 2 Answers

Why not increasing the size of the font in the arrays?

Use for example \large before \begin{array} and adjust the spacing before it (I've used \vspace*{-3cm}).

MWE:

\documentclass[final]{beamer} % beamer 3.10: do NOT use option hyperref={pdfpagelabels=false} !
\mode<presentation> {
\usetheme{default}
}
\usepackage[english]{babel}
\usepackage[latin1]{inputenc}
\usepackage{amsmath,amsthm, amssymb, latexsym}
%\usepackage{times}\usefonttheme{professionalfonts}  % times is obsolete
\usefonttheme[onlymath]{serif}
\boldmath
\usepackage[orientation=portrait,size=a1,scale=2.4,debug]{beamerposter}                       % e.g. for DIN-A0 poster
\title[]{Potenz- und Logarithmengesetze}

\begin{document}
\begin{frame}{}
\vfill
\begin{block}{\Huge\hspace{2cm} Potenzgesetze}\vspace*{-3cm}
$\def\arraystretch{2}\large\begin{array}{rclp{5cm}} a^m \cdot a^m & = &a^{m+n} &\\ \displaystyle \frac{a^m}{a^n} & =& a^{m-n} \\ (a \cdot b)^m & =& a^m \cdot b^m \\ \displaystyle \left(\frac{a}{b}\right)^m & = & \displaystyle \frac{a^m}{b^m} \\ \bigl( a^m \bigr)^n & =& a^{m \cdot n} \\ \end{array}$
\end{block}
\vfill
\begin{block}{\Huge\hspace{2cm} Logarithmengesetze}\vspace*{-3cm}
$\def\arraystretch{2}\large\begin{array}{rcl} \ln(a \cdot b) & = &\ln(a) + \ln(b) \\ \displaystyle \ln\left( \frac{a}{b} \right) & = &\ln(a) - \ln(b) \\ \ln(a^b) & =& b \cdot \ln(a) \\ \ln(e) & = &1 \\ \ln(1) & = &0 \\ \ln(e^x) & = &e^{\ln(x)} = x \end{array}$
\end{block}
\vfill
\end{frame}
\end{document}


Output:

So you want to have a bold font in math mode? You could try the package bm and use it like $\bm{\frac{1}{2}}$. Other solutions: How can I get bold math symbols? ... you can btw change all fonts to bold using \boldmath (after begin document).

One thing is too make them bold. But you could also change the fontsize How to change the font size of a document?