Update textbook.fr.md

01.curriculum/01.physics-chemistry-biology/04.Niv4/04.electromagnetism/02.electromagnetic-waves-vacuum/02.electromagnetic-waves-vacuum-main/textbook.fr.md

@@ -212,13 +212,21 @@ François & 9,7 & Refusé\\
 Gilbert & 18,7 & Admis\\
 Jean & 12,3 & Admis\\
 \end{tabular}`$
--->
+
 
 
 \begin{eqnarray}
 \overrightarrow{E}(\overrightarrow{r},t)=\overrightarrow{E}(\overrightarrow{u}\cdot\overrightarrow{r}-ct)\\
 \overrightarrow{B}(\overrightarrow{r},t)=\overrightarrow{B}(\overrightarrow{u}\cdot\overrightarrow{r}-ct)\\
-\end{eqnarray}
+\end{eqnarray}-->
+
+$`\left \{
+   \begin{array}{r c l}
+      AB  & = & 192 \\
+      C   & = & 5\,896 \\
+      DEF & = & 0,5
+   \end{array}
+   \right .`$
 
 #### Onde plane monochromatique