\begin{cminipage}[fond3] \begin{center}$\ln\left(\frac{1+\tan x}{1-\tan x}\right) = {{2}x + {{4}\over{3}}x^{3}+ O(x^{5})} $\end{center} \end{cminipage} \begin{center}\includegraphics[scale=0.55]{dl05.ps}\end{center}