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 1cde88f16..a6f4fec49 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
@@ -28,4 +28,10 @@ des coordonnées spatiales et la coordonnés temporelle ne change pas le résult
 je peux écrire :
 
 $`\overrightarrow{rot} \, \left( \overrightarrow{rot}\,\overrightarrow{E} \right)=
--\dfrac{\partial}{\partial t} \,\left(\overrightarrow{rot}\overrightarrow{B}\right)`$
\ No newline at end of file
+-\dfrac{\partial}{\partial t} \,\left(\overrightarrow{rot}\overrightarrow{B}\right)`$
+
+$`\overrightarrow{rot} \, \left( \overrightarrow{rot}\,\overrightarrow{E} \right)=
+-\dfrac{\partial}{\partial t} \,\left(\mu_0\;\overrightarrow{j} +
+\mu_0 \epsilon_0 \;\dfrac{\partial \overrightarrow{j}}{\partial t}\right)`$
+
+