6. Let $f(x) = e^x$. Approximate $f'(x)$ at $x = 0$ using the central difference formula for $h = 0.1, 0.05, 0.025, 0.0125, 0.00625$. Print the outputs as a table contains the following columns:
\begin{tabular}{|c|c|}
\hline
$h$ & $f'(0)$ \\
\hline
0.1 & \\
0.05 & \\
0.025 & \\
... & ... \\
\hline
\end{tabular}
