Update cheatsheet.fr.md

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

@@ -910,11 +910,11 @@ figure à faire
     <br>
     *Pour $`z>0`$* :   
     <br>
-    **$`\mathbf{\boldsymbol{\overrightarrow{E}(z) =  \dfrac{\dens^{2D}\,z}{2\epsilon_0} \left(1 - \dfrac{z}{\sqrt{R^2+z^2}}\right)\,\overrightarrow{e_z}}}`$**   
+    **$`\mathbf{\boldsymbol{\overrightarrow{E}(z) =  \dfrac{\dens^{2D}}{2\epsilon_0} \left(1 - \dfrac{z}{\sqrt{R^2+z^2}}\right)\,\overrightarrow{e_z}}}`$**   
     <br>
     *Pour $`z>0`$* :   
     <br>
-    **$`\mathbf{\boldsymbol{\overrightarrow{E}(z) =  \dfrac{\dens^{2D}\,z}{2\epsilon_0} \left(- 1 - \dfrac{z}{\sqrt{R^2+z^2}}\right)\,\overrightarrow{e_z}}}`$**
+    **$`\mathbf{\boldsymbol{\overrightarrow{E}(z) =  \dfrac{\dens^{2D}}{2\epsilon_0} \left(- 1 - \dfrac{z}{\sqrt{R^2+z^2}}\right)\,\overrightarrow{e_z}}}`$**