Tables – How to Create a Comprehensive Table of Signs in LaTeX

Question

I'm pretty new to TeX and LaTeX and to learn I'm trying to copy my handwritten notes from my notebook to a LaTeX document.
I feel like I'm starting to understand how LaTeX works, but I'm certainly not that good at using it.

Basically what I'm trying to achieve is the following table

It is a very basic table of signs, where on the top we have two numbers (-3 and 2) corresponding to the vertical line that divides the cells.
Additionally I would like to add the points as shown in the picture, to show the zeroes.

What I've tried / found so far:

• Creating a table (with \begin{tabular}{c|c|c|c} ... \end{tabular}) doesn't seems to work, I cannot get the numbers to be aligned to the vertical line as I want.
• This question may be related to mine, but the solution provided is too difficult and far different from what I'm trying to achieve.
• This one is even more complicated, and adds to much things that for my case are not useful.

Thanks everyone in advance, I hope to enhance my skills with LaTeX / TeX in the upcoming months.

Answer 1

Not identical to your table, but still quite near.

\documentclass[a4paper]{article}
\usepackage{tkz-tab}
\usepackage{xpatch}

% tkz-tab hardcodes $0$ for the zeros
\xpatchcmd{\tkzTabLine}{$0$}{$\bullet$}{}{}
% we want solid lines
\tikzset{t style/.style={style=solid}}

\begin{document}

\begin{tikzpicture}
\tkzTabInit[lgt=2,espcl=2,deltacl=0]
  { /.8, $3(x-2)^2$ /.8, $x+3$ /.8, $p(x)$ /.8}
  {,$-3$,$2$,} % four main references
\tkzTabLine {,+,t,+,z,+,} % seven denotations
\tkzTabLine {,-,z,+,t,+,}
\tkzTabLine {,-,z,+,z,+,}
\end{tikzpicture}

\end{document}