Update cheatshhet.fr.md

12.temporary_ins/08.conservative-vector-fields/20.conservative-vector-fields-properties/20.overview/cheatshhet.fr.md

@@ -30,7 +30,6 @@ lessons:
 
 ### PHYSIQUE GÉNÉRALE
 
-<br>
 
 ### Définitions et propriétés<br>**Gradient**<br>**Champs vectoriels conservatifs**
 
@@ -51,11 +50,11 @@ GRADIENT  D'UN  CHAMP SCALAIRE
  *Expressions du gradient*
  
  * Coordonnées cartésiennes :   
-   $`\overrightarrow{grad},V=\dfrac{\partial V}{\partial x}\,\overrightarrow{e_x}+\dfrac{\partial V}{\partial y}\,\overrightarrow{e_y}+\dfrac{\partial V}{\partial z}\,\overrightarrow{e_z}`$
+   $`\overrightarrow{grad}\,V=\dfrac{\partial V}{\partial x}\,\overrightarrow{e_x}+\dfrac{\partial V}{\partial y}\,\overrightarrow{e_y}+\dfrac{\partial V}{\partial z}\,\overrightarrow{e_z}`$
  * Coordonnées cylindriques :   
-   $`\overrightarrow{grad},V=\dfrac{\partial V}{\partial \rho}\,\overrightarrow{e_{\rho}}+\dfrac{1}{/rho}\dfrac{\partial V}{\partial \varphi}\,\overrightarrow{e_{\varphi}}+\dfrac{\partial V}{\partial z}\,\overrightarrow{e_z}`$
+   $`\overrightarrow{grad}\,V=\dfrac{\partial V}{\partial \rho}\,\overrightarrow{e_{\rho}}+\dfrac{1}{/rho}\dfrac{\partial V}{\partial \varphi}\,\overrightarrow{e_{\varphi}}+\dfrac{\partial V}{\partial z}\,\overrightarrow{e_z}`$
  * Coordonnées sphériques :   
-   $`\overrightarrow{grad},V=\dfrac{\partial V}{\partial \rho}\,\overrightarrow{e_{\rho}}+\dfrac{1}{/rho}\,\dfrac{\partial V}{\partial \theta}\,\overrightarrow{e_{\theta}}+\dfrac{1}{/rho\,sin\,\theta}\,\dfrac{\partial V}{\partial \varphi}\,\overrightarrow{e_5\varphi}}`$
+   $`\overrightarrow{grad}\,V=\dfrac{\partial V}{\partial \rho}\,\overrightarrow{e_{\rho}}+\dfrac{1}{/rho}\,\dfrac{\partial V}{\partial \theta}\,\overrightarrow{e_{\theta}}+\dfrac{1}{/rho\,sin\,\theta}\,\dfrac{\partial V}{\partial \varphi}\,\overrightarrow{e_5\varphi}`$