Update cheatsheet.fr.md

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

@@ -19,8 +19,8 @@ div\,\overrightarrow{X}}`$**$`\mathbf{\;=\dfrac{d\Phi_X}{d\tau}}`$**$`\;\mathbf{
 }`$**
 
 <br>**$`\mathbf{
-div\,\overrightarrow{X}}\;=\;\color{black}{\dfrac{d\Phi_X}{d\tau}}\;=\;\dfrac{\partial X_x}{\partial x}+\dfrac{\partial X_y}{\partial y}+\dfrac{\partial X_z}{\partial z}
-}`$**
+div\,\overrightarrow{X}}\;\color{black}{=\;\dfrac{d\Phi_X}{d\tau}}\;
+=\;\dfrac{\partial X_x}{\partial x}+\dfrac{\partial X_y}{\partial y}+\dfrac{\partial X_z}{\partial z}}`$**
 
 <br>**$`div\,\overrightarrow{X}\;=\;\color{gray}{\dfrac{d\Phi_X}{d\tau}}\;=\;\dfrac{\partial X_x}{\partial x}+\dfrac{\partial X_y}{\partial y}+\dfrac{\partial X_z}{\partial z}
 `$**