Update cheatsheet.fr.md

12.temporary_ins/08.grad-div-rot/70.combinaisons-of-operators/20.overview/cheatsheet.fr.md

@@ -73,9 +73,9 @@ PRINCIPALES COMBINAISONS
         +\dfrac{1}{\rho^2}\dfrac{\partial^2 \phi}{\partial \varphi^2}+\dfrac{\partial^2 \phi}{\partial z^2}`$
       * coordonnées sphérique $`(r\,,\,\theta\,,\,\varphi)`$ :   
         <br>
-       $`\Delta\,\phi=\dfrac{1}{r}\dfrac{\partial^2}{\partial r^2}(r\phi)
-         + \dfrac{1}{r^2\,\sin\theta}\dfrac{\partial}{\partial \theta}\left(\sin\theta\dfrac{\partial \phi}{\partial \theta}\right)
-         + \dfrac{1}{r^2\,\sin^2\theta}\dfrac{\partial^2 \phi}{\partial \varphi^2}`$
+       $`\Delta\,\phi=\dfrac{1}{r}\dfrac{\partial^2}{\partial r^2}(r\phi)+
+         \dfrac{1}{r^2\,\sin\theta}\dfrac{\partial}{\partial \theta}\left(\sin\theta\dfrac{\partial \phi}{\partial \theta}\right)+
+         \dfrac{1}{r^2\,\sin^2\theta}\dfrac{\partial^2 \phi}{\partial \varphi^2}`$
 
 
    ---