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

@@ -113,6 +113,15 @@ Ecriture générale de son vecteur accélération $`\overrightarrow{a_M}`$
 $`\overrightarrow{a_M}=\dpt{\overrightarrow{v_M}}=\ddpt{\overrightarrow{OM}}`$   
 <br>
 $`\displaystyle\begin{align}\quad\quad =\ddpt{\overrightarrow{OO'}}
-& +\sum_{i=1}^3 \Big(\ddpt{\alpha_{iM}}\cdot\overrightarrow{e_{\alpha_{i}}}_M\\+ \dpt{\alpha_{iM}}\cdot\dpt{\overrightarrow{e_{\alpha_{i}}}}_M\Big) \\
+& +\sum_{i=1}^3 \Big(\ddpt{\alpha_{iM}}\cdot\overrightarrow{e_{\alpha_{i}}}_M + \dpt{\alpha_{iM}}\cdot\dpt{\overrightarrow{e_{\alpha_{i}}}}_M\Big) \\
 & +\sum_{i=1}^3 \Big(\dpt{\alpha_{iM}}\cdot\dpt{\overrightarrow{e_{\alpha_{i}}}}_M + \alpha_{iM}\cdot\ddpt{\overrightarrow{e_{\alpha_{i}}}}_M\Big)
-\end{align}`$ 
+\end{align}`$   
+<br>
+$`\displaystyle\begin{align}\quad\quad =\ddpt{\overrightarrow{OO'}}
+& +\sum_{i=1}^3 \Big(\ddpt{\alpha_{iM}}\cdot\overrightarrow{e_{\alpha_{i}}}_M \\
+& + 2\times \sum_{i=1}^3 \Big(\dpt{\alpha_{iM}}\cdot\dpt{\overrightarrow{e_{\alpha_{i}}}}_M \\
+& + \sum_{i=1}^3 \alpha_{iM}\cdot\ddpt{\overrightarrow{e_{\alpha_{i}}}}_M
+\end{align}`$
+
+
+