\def\taille{\vrule height 20pt depth 20pt width 0pt }
    \begin{tabular}{*{4}{|>{\centering}p{3cm}}|}
    \hline
    \taille $a$ & $b$ & $c$ & $d$\cr
    \hline
    \end{tabular}

\begin{spreadtab}{{tabular}{|c|*{13}{c|}}}
 \hline
 @$x$ & 0 & \STcopy{>}{b1+0.5} & & & & & & & & &&&\\\hline
 @$f(x)$ & \STcopy{>}{-0.08*b1*b1+0.8*b1+1.92} & & & & & & & & &&&&\\\hline
\end{spreadtab}