Update cheatsheet.fr.md

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

@@ -863,21 +863,19 @@ $`\quad\boldsymbol{\mathbf{=\color{brown}{2\,A\cdot cos\Big(\dfrac{\varphi_1-\va
   <br>
   $`\color{blue}{\scriptsize{\quad\text{mettons en commun les termes qui peuvent l'être}}}`$   
   <br>
-  $`\quad =A\;\big[ \,e^{\,i\;(\omega t\,-\, kx)}\,\big(\,e^{\,i\varphi_1}\,+\,e^{\,i\varphi_1}\big)`$   
+  $`\quad =A\;e^{\,i\;(\omega t\,-\, kx)}`$ $`\cdot\big(\,e^{\,i\varphi_1}\,+\,e^{\,i\varphi_1}\big)`$   
   <br>
-  $`\quad =A\;\big[ \,e^{\,i\;(\omega t\,-\, kx)}
-   \,\left[\,e^{\,i\left(\frac{\varphi1 + \varphi2}{2}\;+\;\frac{\varphi1-\varphi2}{2}\right)
+  $`\quad =A\;e^{\,i\;(\omega t\,-\, kx)}
+   \cdot\left(\,e^{\,i\left(\frac{\varphi1 + \varphi2}{2}\;+\;\frac{\varphi1-\varphi2}{2}\right)
    }
    \,+\,
-   e^{\,i\;\left(\frac{\varphi1 + \varphi2}{2}\;-\;\frac{\varphi1-\varphi2}{2}\right)}\right]`$   
+   e^{\,i\;\left(\frac{\varphi1 + \varphi2}{2}\;-\;\frac{\varphi1-\varphi2}{2}\right)}\right)`$   
    <br>
    $`\color{blue}{\scriptsize{\quad \text{utilisons } exp\,(a+b)\;=\; exp\,(a)\;+\; exp\,(b)}}`$  
    $`\color{blue}{\scriptsize{\quad\text{et regroupons encore les termes communs.}}}`$   
    <br>
-   $`A\;\big[ \,e^{\,i\;(\omega t\,-\, kx)\,e^{\,i\left(\frac{\varphi1 + \varphi2}{2}\right)}
-   \,\big(\,e^{\,i\left(\frac{\varphi1-\varphi2}{2}\right)}
-   \,+\,
-   e^{\,-\,,i\;\left(\dfrac{\varphi1-\varphi2}{2}\right)}\big)`$
+   $`A\;e^{\,i\;(\omega t\,-\, kx)\,e^{\,i\left(\frac{\varphi1 + \varphi2}{2}\right)}`$
+   $`\cdot\big(\,e^{\,i\left(\frac{\varphi1-\varphi2}{2}\right)}\,+\,e^{\,-\,,i\;\left(\frac{\varphi1-\varphi2}{2}\right)}\big)`$