Merge branch 'demo2-master-patch-69199' into 'master'

juste correction bug d'affichage d'une équation trop longue pour smartphone

See merge request !42

00.brainstorming-pedagogical-teams/40.collection-existing-pedagogical-content/10.mathematical-tools/10.vector-analysis/main/textbook.fr.md

@@ -666,7 +666,8 @@ $`\;\Longrightarrow\left|\begin{array}{l}\overrightarrow{U}\cdot\overrightarrow{
 $`\forall \overrightarrow{U}\in\mathcal{P}\quad, \forall \overrightarrow{V}\in\mathcal{P}`$
 $`\overrightarrow{U}\perp\overrightarrow{V}\Longleftrightarrow\widehat{\overrightarrow{U},
 \overrightarrow{V}}=\dfrac{\pi}{2}\Longleftrightarrow cos(\widehat{\overrightarrow{U},
-\overrightarrow{V}})=0`$**$`\Longrightarrow\overrightarrow{U}\cdot\overrightarrow{V}=0`$**.
+\overrightarrow{V}})=0`$
+**$`\Longrightarrow\overrightarrow{U}\cdot\overrightarrow{V}=0`$**.
 
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