Update textbook.fr.md

00.brainstorming-pedagogical-teams/40.collection-existing-pedagogical-content/05.classical-mechanics/vector-analysis/textbook.fr.md

@@ -513,13 +513,14 @@ $`(\vec{e_1},\vec{e_2},...,\vec{e_n})`$ est une base orthonormée
 $`\displaystyle\quad\forall \overrightarrow{U}\in\mathcal{P}\quad \overrightarrow{U}=\sum_{i=1}^n\;U_i\cdot\vec{e_i}`$ 
 $`\displaystyle\quad\forall \overrightarrow{V}\in\mathcal{P}\quad \overrightarrow{V}=\sum_{i=1}^n\;V_i\cdot\vec{e_i}`$  
 
-* For the expression of a vector $`\vec{U}`$ in the base $`(\vec{e_1},\vec{e_2},...,\vec{e_n})`$,
-we should use (?) (http://www.electropedia.org/iev/iev.nsf/display?openform&ievref=102-03-04) : <br>
-$`\overrightarrow{U}=\left(\begin{array}{l}U_1\\U_2\\U_3)\end{array}\right)`$
-instead of $`\overrightarrow{U}=\left|\begin{array}{l}U_1\\U_2\\U_3)\end{array}\right.`$
-
-* méthode des produits en croix :
-
+* [FR] For the expression of a vector $`\vec{U}`$ in the base $`(\vec{e_1},\vec{e_2},...,\vec{e_n})`$,
+we shouldn't we use (http://www.electropedia.org/iev/iev.nsf/display?openform&ievref=102-03-04) : <br>
+$`\overrightarrow{U}=\left(\begin{array}{l}U_1\\U_2\\U_3\end{array}\right)`
+$`\displaystyle\overrightarrow{U}=\left(\begin{array}{l}U_1\\U_2\\U_3\end{array}\right)`$
+instead of $`\overrightarrow{U}=\left|\begin{array}{l}U_1\\U_2\\U_3\end{array}\right.`$ as we do at INSA ?
+
+* [ES]  <br>
+[FR] méthode des produits en croix :<br>
 $`\forall\overrightarrow{U}=\left(\begin{array}{l}U_1\\U_2\\U_3)\end{array}\right)`$ et
 $`\forall\overrightarrow{V}=\left(\begin{array}{l}U_1\\U_2\\U_3)\end{array}\right)`$
 $`$`\vec{U}\land\vec{V}=`$