# Two equations in a block of table

I make a table, 2*2，

\begin{center}
\begin{table}[H]
\centering
\begin{tabular}{|c|c|} \hline

$F=ax$ &  \nabla F =a $\\ \hline$G=a+b\\ K=a+c$&$ H=c+d\end{tabular} \end{table} \end{center}  The above code generates mistakes. In 2*1 block I want a 2 line equation. So I try \align,\equation and so on. For example, \begin{center} \begin{table}[H] \centering \begin{tabular}{|c|c|} \hlineF=ax$& \nabla F =a$         \\ \hline
\begin{align*}G&=a+b\\ K&=a+c\end{align*} &  $H=c+d$

\end{tabular}
\end{table}
\end{center}


But this makes mistake too. So I have to use $$, but I do not know how to write two equation in $$.

By the way, even this makes mistakes.

\begin{center}
\begin{table}[H]
\centering
\begin{tabular}{|c|c|} \hline

$F=ax$ &  \nabla F =a $\\ \hline \begin{equation*}G=a+b \end{equation*} &$ H=c+d$\end{tabular} \end{table} \end{center}  - Could you post an image (even handmade) of what you are trying to achieve? – karlkoeller Sep 30 '13 at 15:09 @karlkoeller, yes, of course. – Vivian Sep 30 '13 at 15:17 ## 2 Answers I'm sorry, but I can not recognize your handwriting. Do you mean something like this? Code: \documentclass{article} \begin{document} \begin{table} \centering$ \begin{array}{|c|c|}
\hline
F(x) & G(x) \\
\hline
F(N) & G(N) \\
N=a & N=a \\
\hline
\end{array} $\end{table} \end{document}  - I'm not sure I understand fully what you're trying to achieve since you refer to a 2x2 table in one place and a 2x1 table in another. Since the contents of the table would appear to be math expressions, you may want to use an array instead of a tabular environment. For a 2x2 table you could proceed along the following lines: \documentclass{article} \begin{document} \begin{table} \centering$ \begin{array}{|c|c|}
\hline
F & \nabla F \\
\hline
G & \nabla G \\
\hline
\end{array} \$
\end{table}
\end{document}

-
,Thank you very much for your answer. I want two equation in the block of the second row and the first and second column. –  Vivian Sep 30 '13 at 15:22
@Vivian - Do you mean you want the material in the cells be typeset in display style? If so, just insert \displaystyle at the beginning of the cells. –  Mico Sep 30 '13 at 15:28
please see my picture. My poor non genuine English. –  Vivian Sep 30 '13 at 15:32