Update cheatsheet.fr.md

12.temporary_ins/69.waves/30.n3/20.overview/cheatsheet.fr.md

@@ -1705,18 +1705,18 @@ $`\quad\quad \;\; = \cdots`$
   <br>
   $`U(\overrightarrow{r},t)\,=\,\mathscr{R}e\big[\underline{U}(\overrightarrow{r},t)\big]`$   
   <br>
-  $`\begin{array}\quad = &\mathscr{R}e\big[\,2\,A_{moy}\,cos(\theta_{12})\; e^{\,i\,\theta_{moy}}\\
-   &-\,2i\,\Delta A_{1-2}\,sin(\theta_{12})\; e^{\,i\,\theta_{moy}}\big]\end{array}`$   
+  $`\begin{align}\; = &\mathscr{R}e\big[\,2\,A_{moy}\,cos(\theta_{12})\; e^{\,i\,\theta_{moy}}\\
+   &-\,2i\,\Delta A_{1-2}\,sin(\theta_{12})\; e^{\,i\,\theta_{moy}}\big]\end{align}`$   
   <br>
   $`\color{blue}{\scriptsize{\quad\text{Utilisons }\;exp(ia)\,=\, cos\,a\,+\,i\, sin\,a}}`$  
   <br>   
-  $`\begin{array}\quad = &\mathscr{R}e \big[\,2\,A_{moy}\,cos(\theta_{12})\;(cos\,\theta_{moy}\,+\,i\,sin\,\theta_{moy})\\
-   &-\,2i\,\Delta A_{1-2}\,sin(\theta_{12})\;(cos\,\theta_{moy}\,+\,i\,sin\,\theta_{moy})\big]\end{array}`$  
+  $`\begin{align}\;= &\mathscr{R}e \big[\,2\,A_{moy}\,cos(\theta_{12})\;(cos\,\theta_{moy}\,+\,i\,sin\,\theta_{moy})\\
+   &-\,2i\,\Delta A_{1-2}\,sin(\theta_{12})\;(cos\,\theta_{moy}\,+\,i\,sin\,\theta_{moy})\big]\end{align}`$  
   <br>
-  $`\begin{array}\quad = &2\times\mathscr{R}e \big[\\
+  $`\begin{align}\; = &2\times\mathscr{R}e \big[\\
   \,(\,A_{moy}\,cos(\theta_{12})\;cos\,\theta_{moy}\,+\,\Delta A_{1-2}\,sin(\theta_{12}\;sin\,\theta_{moy}\,) \\
   \,+\,i\,(\,A_{moy}\,cos(\theta_{12})\;sin\,\theta_{moy}\,-\,\Delta A_{1-2}\,sin(\theta_{12}\;sin\,\theta_{moy}\,)\big] \\
-  \end{array}`$    
+  \end{align}`$