Update cheatsheet.fr.md

12.temporary_ins/08.grad-div-rot/20.div/20.overview/cheatsheet.fr.md

@@ -19,12 +19,20 @@ visible: false
 
 ##### Expression de la divergence en coordonnées cylindriques
 
+<br>**$`\boldsymbol{\mathbf{div\,\overrightarrow{X}\;\color{black}{=\;\dfrac{d\Phi_X}{d\tau}}\;=\;\dfrac{1}{\rho}\;\dfrac{\partial\,(\,\rho\,X_{\rho})}{\partial\,\rho}
++\dfrac{1}{\rho}\;\dfrac{\partial\,X_{\varphi}}{\partial\,\varphi}+\dfrac{\partial\,X_{z}}{\partial\,z}}}`$**
+
 <br>**$`div\,\overrightarrow{X}\;\color{gray}{=\;\dfrac{d\Phi_X}{d\tau}}\;=\;\dfrac{1}{\rho}\;\dfrac{\partial\,(\,\rho\,X_{\rho})}{\partial\,\rho}
 +\dfrac{1}{\rho}\;\dfrac{\partial\,X_{\varphi}}{\partial\,\varphi}+\dfrac{\partial\,X_{z}}{\partial\,z}`$**
 
-
 ##### Expression de la divergence en coordonnées sphériques
 
+<br>**$`\mathbf{\boldsymbol{div\,\overrightarrow{X}\color{gray}{\;=\dfrac{d\Phi_X}{d\tau}}\,=
+\; &\dfrac{1}{r^2}\;\dfrac{\partial\,(r^2\,X_r}{\partial\,r)}}}`$
+<br>**$`\mathbf{\boldsymbol{+ \dfrac{1}{r\,sin\,\theta}\;\dfrac{\partial\,(sin\,\theta\,X_{\theta})}{\partial\,\theta}}}`$**
+<br>**$`\mathbf{\boldsymbol{+ \dfrac{1}{r\,sin\,\theta}\;\dfrac{\partial\,X_{\varphi}}{\partial\,\varphi}\end{align}}}`$**
+
+
 <br>**$`\mathbf{\boldsymbol{\begin{align}
 div\,\overrightarrow{X}\color{gray}{\;=\dfrac{d\Phi_X}{d\tau}}\,=\; &\dfrac{1}{r^2}\;\dfrac{\partial\,(r^2\,X_r}{\partial\,r)}\\
 & \quad\quad + \dfrac{1}{r\,sin\,\theta}\;\dfrac{\partial\,(sin\,\theta\,X_{\theta})}{\partial\,\theta}\\