Update cheatsheet.fr.md

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

@@ -520,7 +520,7 @@ $`\begin{align}
 <br>
 $`=-\displaystyle\,\int_A^B \alpha\,\big(\underbrace{\overrightarrow{grad}\,\phi_X\cdot\overrightarrow{dl}}_{=\;d\phi\;,\text{ dfn de } \overrightarrow{grad}\,\phi}\big)`$
 <br>
-$`=-\displaystyle\,\int_A^B \alpha\,\underbrace{\big(\overrightarrow{grad}\,\phi_X\cdot\overrightarrow{dl}}_{=\;d\phi\;,\text{ dfn de } \overrightarrow{grad}\,\phi\big)}`$
+$`=-\displaystyle\,\int_A^B \alpha\,\underbrace{\big(\overrightarrow{grad}\,\phi_X\cdot\overrightarrow{dl}\big)}_{=\;d\phi\;,\text{ dfn de } \overrightarrow{grad}\,\phi}`$
 
 
 #### Qu'est-ce que la circulation d'un champ vectoriel le long d'un chemin ?