diff --git a/01.curriculum/01.physics-chemistry-biology/04.Niv4/04.electromagnetism/02.electromagnetic-waves-vacuum/02.electromagnetic-waves-vacuum-main/textbook.fr.md b/01.curriculum/01.physics-chemistry-biology/04.Niv4/04.electromagnetism/02.electromagnetic-waves-vacuum/02.electromagnetic-waves-vacuum-main/textbook.fr.md
index f07d45499..34b0e5115 100644
--- a/01.curriculum/01.physics-chemistry-biology/04.Niv4/04.electromagnetism/02.electromagnetic-waves-vacuum/02.electromagnetic-waves-vacuum-main/textbook.fr.md
+++ b/01.curriculum/01.physics-chemistry-biology/04.Niv4/04.electromagnetism/02.electromagnetic-waves-vacuum/02.electromagnetic-waves-vacuum-main/textbook.fr.md
@@ -308,7 +308,7 @@ quelconque de l'espace, est :
 
 * pour le champ électrique :<br>
 <br>
- $`\overrightarrow{E}=\left|
+$`\overrightarrow{E}=\left|
    \begin{array}{r c l}
       E_x=E_O\cdot cos(\pm\,\overrightarrow{k}\cdot\overrightarrow{r}\pm \omega\,t+\phi_x))\\
       E_y=E_O\cdot cos(\pm\,\overrightarrow{k}\cdot\overrightarrow{r}\pm \omega\,t+\phi_y))\\
@@ -318,7 +318,7 @@ quelconque de l'espace, est :
 
 * pour le champ magnétique :<br>
 <br>
- $`\overrightarrow{B}=\left|
+$`\overrightarrow{B}=\left|
    \begin{array}{r c l}
       B_x=E_O\cdot cos(\pm\,\overrightarrow{k}\cdot\overrightarrow{r}\pm \omega\,t+\phi_x))\\
       B_y=E_O\cdot cos(\pm\,\overrightarrow{k}\cdot\overrightarrow{r}\pm \omega\,t+\phi_y))\\