Update textbook.fr.md

12.temporary_ins/40.classical-mechanics/30.n3/42.point-dynamics-applications/05.point-dynamics-method/10.main/textbook.fr.md

@@ -118,8 +118,8 @@ $`\displaystyle\begin{align}\quad\quad =\ddpt{\overrightarrow{OO'}}
 \end{align}`$   
 <br>
 $`\displaystyle\begin{align}\quad\quad =\ddpt{\overrightarrow{OO'}}
-& +\sum_{i=1}^3 \Big(\ddpt{\alpha_{iM}}\cdot\overrightarrow{e_{\alpha_{i}}}_M \\
-& + 2\times \sum_{i=1}^3 \Big(\dpt{\alpha_{iM}}\cdot\dpt{\overrightarrow{e_{\alpha_{i}}}}_M \\
+& +\sum_{i=1}^3 \ddpt{\alpha_{iM}}\cdot\overrightarrow{e_{\alpha_{i}}}_M \\
+& + \Big( 2\times \sum_{i=1}^3 \dpt{\alpha_{iM}}\cdot\dpt{\overrightarrow{e_{\alpha_{i}}}}_M \Big) \\
 & + \sum_{i=1}^3 \alpha_{iM}\cdot\ddpt{\overrightarrow{e_{\alpha_{i}}}}_M
 \end{align}`$