diff --git a/12.temporary_ins/05.coordinates-systems/40.spherical-coordinates/10.main/textbook.fr.md b/12.temporary_ins/05.coordinates-systems/40.spherical-coordinates/10.main/textbook.fr.md
index e96a38f2d..69613c6e7 100644
--- a/12.temporary_ins/05.coordinates-systems/40.spherical-coordinates/10.main/textbook.fr.md
+++ b/12.temporary_ins/05.coordinates-systems/40.spherical-coordinates/10.main/textbook.fr.md
@@ -409,7 +409,7 @@ $`=
 \end{array} \right.\quad`$
 $`=-\,\overrightarrow{e_{\rho}}`$
 
-avec $`\overrightarrow{e_{\rho}}`$ vecteur de la base cylindrique  :
+où $`\overrightarrow{e_{\rho}}`$ est le vecteur de la base cylindrique  :
 $`(\overrightarrow{e_{\rho}}, \overrightarrow{e_{\phi}}, \overrightarrow{e_z})`$. 
 
 $`\dfrac{d\overrightarrow{e_r}}{dt}=\dfrac{\partial\overrightarrow{e_r}}{\partial\theta}\cdot \dfrac{d\theta}{dt}\;+\;\dfrac{\partial\overrightarrow{e_r}}{\partial\varphi}\cdot \dfrac{d\varphi}{dt}\quad`$