Update cheatsheet.fr.md

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

@@ -342,14 +342,11 @@ $`\forall \alpha \in \mathbb{R}\;,\,`$ **$`\large{exp{\,\alpha} = cos \,\alpha +
      3D : *$`\quad\large{\boldsymbol{\mathbf{U(\vec{r},t)=A\cdot cos\,(\omega t - \vec{k}\cdot\vec{r} + \varphi)}}}`$*   
 
    * soit en **notation complexe** :  
-      1D : $`\begin{align}
-       \quad\color{brown}{\large{\boldsymbol{\mathbf{\underline{U}(x,t)}}}} &= A\cdot e^{\,i\,(\omega t - k x + \varphi)}\\
-        &\color{blue}{\scriptsize{\quad\quad exp(a+b) = exp(a)\times exp(b)}}\\
-        &\\
-        &=A\;e^{\,i\,\varphi}\cdot e^{\,i\,(\omega t - kx)}\\  
-        &\\
-        &\color{brown}{\boldsymbol{\mathbf{\large{=\underline{A}\cdot e^{\,i\,(\omega t - kx)}}}}}
-        \end{align}`$   
+      1D : **$`\quad\large{\boldsymbol{\mathbf{\underline{U}(x,t)}}`$** $`\;= A\cdot exp\,[\,i\,(\underbrace{\omega t - k x + \varphi}_{\color{blue}{exp(a+b) = exp(a)\times exp(b)}})\,]`$   
+           <br>
+          $`\quad\quad\quad\quad\quad\quad =\underbrace{A\;e^{\,i\,\varphi}}_{\color{blue}{\underline{A}=A\; exp (\,i\varphi))}}\cdot exp\,[\,i\,(\omega t - kx)\,]`$
+           <br>
+          **$`\quad\quad\quad\quad\quad\quad\boldsymbol{\mathbf{\large{=\underline{A}\cdot e^{\,i\,(\omega t - kx)}}}}`$**    
      <br>
       3D : **$`\quad\large{\boldsymbol{\mathbf{\underline{U}(\vec{r},t)=\underline{A}\cdot e^{\,i\,(\omega t - \vec{k}\cdot\vec{r})}}}}`$**   
      <br>