I'm modifying this code to have an arrow as in the picture. I'm tried but unable to reach my goal. Please help me modify it! Thank you so much!
\documentclass[12pt]{extreport}
\usepackage[left = 1in, right = 1in, top = 0.7in, bottom = 0.7in]{geometry}
\usepackage{graphicx,latexsym,mathtools}
\usepackage{tikz,tkz-tab}
\begin{document}
\begin{tikzpicture}
\tkzTab
[lgt=5,espcl=3]
{$x$/1, $f_\alpha'(x)$/1, $f_\alpha(x)$/3}
{$0$, $\alpha-1$, $x^*(\alpha)$, $+\infty$}
{,+,0,-,-,-,}
{-/ $0$, +/ $f_\alpha(\alpha-1)$, -/ $0$ , -/ $-\infty$}
\end{tikzpicture}
\end{document}
+ infinity
? – AndréC Feb 21 '20 at 22:23- infinity
. – LE Anh Dung Feb 21 '20 at 22:24