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Update 12.temporary_ins/10.electrostatics-vacuum/40.gauss-theorem-applications/05.gauss-symetries-invariances/10.main/textbook.fr.md

12.temporary_ins/10.electrostatics-vacuum/40.gauss-theorem-applications/05.gauss-symetries-invariances/10.main/textbook.fr.md

@@ -159,6 +159,13 @@ Si de plus la distribution de charge $`\dens`$ est invariante par toute variatio
 \end{array}
 \right\}}`$$`\mathbf{\Longrightarrow \dens = \dens (\beta)\Longrightarrow \overrightarrow{E}=\overrightarrow{E}\,(\beta)}`$**
 
+**$`\require{cancel}\begin{align}\left.
+\begin{array}{l}
+\dens\,(\xcancel{\alpha},\beta, \gamma) =\dens\,(\beta,\gamma) \\
+\dens\,(\alpha,\beta, \xcancel{\gamma}) =\dens\,(\alpha,\beta)
+\end{array}\right\}&\Longrightarrow \boldsymbol{\mathbf{\dens = \dens (\beta)}}\\
+&\Longrightarrow \boldsymbol{\mathbf{\overrightarrow{E}=\overrightarrow{E}\,(\beta)}}
+\end{align}`$**