Update cheatsheet.fr.md

12.temporary_ins/10.electrostatics-vacuum/20.causes-stationary-electric-field/20.overview/cheatsheet.fr.md

@@ -784,13 +784,15 @@ figure à faire
     \times
     \int_{\rho=0}^{R} \rho\,(\rho^2+z_M^2)^{\,-3/2}\,d\rho`$    
     <br>
-    $`\displaystyle \hspace{1cm} =  \dfrac{\dens^{2D}\,z}{2\epsilon_0} \int_{\rho = 0}^R -\Big(\underbrace{(-\dfrac{1}{2}\Big)}_{n+1}\times
+    $`\displaystyle \hspace{1cm} =  \dfrac{\dens^{2D}\,z}{2\epsilon_0} \int_{\rho = 0}^R -\Big(\underbrace{-\dfrac{1}{2}\Big}_{n+1})\cdot
     \underbrace{2\rho}_{u^{\,'}}\,\underbrace{(\rho^2+z^2)^{-\,3/2}}_{u^n}\,d\rho`$   
     <br>
-    $`\color{blue}{\scriptsize{\text{le signe moins devant } (n+1)\cdot u^n \cdot u' \text{ devient un plus en inversant les bornes d'intégration}}}`$ 
+    $`\displaystyle \hspace{1cm} =  - \dfrac{\dens^{2D}\,z}{2\epsilon_0} \big[(\rho^2+z^2)^{-\,1/2}\big]_0^R`$  
     <br>
-    $`\displaystyle \hspace{1cm} =  \dfrac{\dens^{2D}\,z}{2\epsilon_0} \big[\underbrace{\dfrac{1}{2}\times\dfrac{1}{-3/2+1}}
-    _{=\frac{1}{2}\,\times \,(-2) \,=\, -1}(\rho^2+z^2)^{-\,1/2}\big]_0^R`$   
+    $`\color{blue}{\scriptsize{\text{le signe moins devant } (n+1)\cdot u^n \cdot u'}}`$
+    $`\color{blue}{\scriptsize{\text{ devient plus en inversant les bornes d'intégration}}}`$   
+    <br>
+    $`\displaystyle \hspace{1cm} = +\dfrac{\dens^{2D}\,z}{2\epsilon_0} \big[(\rho^2+z^2)^{-\,1/2}\big]_R^0`$   
     <br>
     $`\displaystyle \hspace{1cm} =  \dfrac{\dens^{2D}\,z}{2\epsilon_0} \left(\dfrac{1}{|z|} - \dfrac{1}{\sqrt{\rho^2+z^2}}\right)`$   
     <br>