Update cheatsheet.fr.md

12.temporary_ins/08.conservative-vector-fields/20.conservative-vector-fields-properties/20.overview/cheatsheet.fr.md

@@ -408,14 +408,21 @@ $`\begin{align}
 \; &= X_{\alpha}\,dl_{\alpha}\,\big(\overrightarrow{e_{\alpha}}\cdot\overrightarrow{e_{\alpha}}\big)
 +X_{\alpha}\,dl_{\beta}\,\big(\overrightarrow{e_{\alpha}}\cdot\overrightarrow{e_{\beta}}\big)
 +X_{\alpha}\,dl_{\gamma}\,\big(\overrightarrow{e_{\alpha}}\cdot\overrightarrow{e_{\gamma}}\big)\\
-&\quad + X_{\beta}\,dl_{\alpha}\,\big(\overrightarrow{e_{\beta}}\cdot\overrightarrow{e_{\alpha}}\big)
+&\; + X_{\beta}\,dl_{\alpha}\,\big(\overrightarrow{e_{\beta}}\cdot\overrightarrow{e_{\alpha}}\big)
 +X_{\beta}\,dl_{\beta}\,\big(\overrightarrow{e_{\beta}}\cdot\overrightarrow{e_{\beta}}\big)
 +X_{\beta}\,dl_{\gamma}\,\big(\overrightarrow{e_{\beta}}\cdot\overrightarrow{e_{\gamma}}\big)\\
-&\quad + X_{\gamma}\,dl_{\alpha}\,\big(\overrightarrow{e_{\gamma}}\cdot\overrightarrow{e_{\alpha}}\big)
+&\; + X_{\gamma}\,dl_{\alpha}\,\big(\overrightarrow{e_{\gamma}}\cdot\overrightarrow{e_{\alpha}}\big)
 +X_{\gamma}\,dl_{\beta}\,\big(\overrightarrow{e_{\gamma}}\cdot\overrightarrow{e_{\beta}}\big)
 +X_{\gamma}\,dl_{\gamma}\,\big(\overrightarrow{e_{\gamma}}\cdot\overrightarrow{e_{\gamma}}\big)\\
 \end{align}`$
 
+$`\color{brown}{\large{\mathbf{X_{\alpha}\,dl_{\alpha}+X_{\beta}\,dl_{\beta}+X_{\gamma}\,dl_{\gamma}}}}`$
+
+Par ailleurs,$`\phi`$ étant un champ scalaire, sa différentielle exprimée en coordonnées $`(\alpha\,,\beta\,,\gamma)`$ s'écrit :
+
+$`\color{blue}{\large{\mathbf{d\phi=\left.\dfrac{\partial \phi}{\partial \alpha}\right|_M\cdot dl_{\alpha} + \left.\dfrac{\partial \phi}{\partial \beta}\right|_M\cdot dl_{\beta} + \left.\dfrac{\partial \phi}{\partial \gamma}\right|_M\cdot dl_{\gamma}}}}`$
+
+