diff --git a/00.brainstorming-pedagogical-teams/40.collection-existing-pedagogical-content/05.classical-mechanics/vector-analysis/textbook.fr.md b/00.brainstorming-pedagogical-teams/40.collection-existing-pedagogical-content/05.classical-mechanics/vector-analysis/textbook.fr.md
index 3d8ff588a..7ab6e26b9 100644
--- a/00.brainstorming-pedagogical-teams/40.collection-existing-pedagogical-content/05.classical-mechanics/vector-analysis/textbook.fr.md
+++ b/00.brainstorming-pedagogical-teams/40.collection-existing-pedagogical-content/05.classical-mechanics/vector-analysis/textbook.fr.md
@@ -661,8 +661,13 @@ $`2\,t\,dt\cdot\overrightarrow{e_x}
 
 
 
-
 #### Dérivée d’un vecteur par rapport au temps
 
+Por INSA / pour l'INSA / for INSA :
+
+$`\displaystyle\dfrac{d\left(\overrightarrow{OM}\right)(t)}{dt}=\lim_{\Delta t\rightarrow 0}
+\left(\dfrac{\overrightarrow{OM}\right)(t+\Delta t)-\overrightarrow{OM}\right)(t))}{\Delta t}`$
+
+