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 5d4b0196a..f07d45499 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
@@ -307,11 +307,8 @@ dans un repère cartésien $`(O, \overrightarrow{e_x}, \overrightarrow{e_y}, \ov
 quelconque de l'espace, est :
 
 * pour le champ électrique :<br>
- 
-
-
-
-$`\overrightarrow{E}\left|
+<br>
+ $`\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))\\
@@ -319,8 +316,15 @@ $`\overrightarrow{E}\left|
    \end{array}
    \right.`$
 
-
-
+* pour le champ magnétique :<br>
+<br>
+ $`\overrightarrow{B}=\left|
+   \begin{array}{r c l}
+      B_x=E_O\cdot cos(\pm\,\overrightarrow{k}\cdot\overrightarrow{r}\pm \omega\,t+\phi_x))\\
+      B_y=E_O\cdot cos(\pm\,\overrightarrow{k}\cdot\overrightarrow{r}\pm \omega\,t+\phi_y))\\
+      B_z=E_O\cdot cos(\pm\,\overrightarrow{k}\cdot\overrightarrow{r}\pm \omega\,t+\phi_z))\\
+   \end{array}
+   \right.`$
 <!--
 $`\overrightarrow{E}(\pm\,\overrightarrow{k}\cdot\overrightarrow{r}\pm \omega\,t)\quad`$
 et $`\quad\overrightarrow{B}(\pm\,\overrightarrow{k}\cdot\overrightarrow{r}\pm \omega \,t))`$