# TikZ-PGF – Creating Tables of Signs and Variations with tkz-tab

tikz-pgf

I have a serious problem to solve. I would like to make a function monotonicity in my latex doc and i write

\begin{tikzpicture}
\tikzset{arrow style/.style = {blue,
->,
> = latexâ€™,
shorten > = 6pt,
shorten < = 6pt}}
\tkzTabInit[espcl=5]{$x$ /1, $\ln x +1$ /1.5, $x \ln x$ /2}%
{$0$ ,$1/\E$ , $+\infty$}%
\tkzTabLine{d,-,z,+,}
\tkzTabVar%
{ D+/ / $0$ ,%
-/ \colorbox{black}{\textcolor{white}{$\dfrac{-1}{e}$}}/ ,%
+/ $+\infty$ / }%
\end{tikzpicture}


and it shows error. Is something with any package or some setting i have to to in the doc??

I sent you an exact example of what i try to do

#### Best Answer

Firstly it's preferable to give a complete example, then you need to define \E, you need to load amsmath.

\documentclass[11pt]{scrartcl}
\usepackage{tikz,tkz-tab,amsmath}
\usetikzlibrary{arrows}

\begin{document}
\newcommand{\E}{\mathrm{e}}
\begin{tikzpicture}
\tikzset{arrow style/.style = {blue,->,> = latex',
shorten > = 6pt,
shorten < = 6pt}}
\tkzTabInit[espcl=5]{$x$ /1, $\ln x +1$ /1.5, $x \ln x$ /2}{$0$ ,$1/\E$ , $+\infty$}%
\tkzTabLine{d,-,z,+,}
\tkzTabVar%
{ D+/ / $0$ ,%
-/ \colorbox{black}{\textcolor{white}{$\dfrac{-1}{e}$}}/ ,+/ $+\infty$ / }%
\end{tikzpicture}
\end{document}