Update cheatsheet.fr.md

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

@@ -628,11 +628,23 @@ $`\quad\boldsymbol{\mathbf{=\color{brown}{2\,A\cdot cos\Big(\dfrac{\varphi_1-\va
   $`\color{blue}{\scriptsize{ \quad\text{En posant  } p=a+b \text{ et  } q=a-b\;,}}`$   
   $`\color{blue}{\scriptsize{\quad \text{nous obtenons  } a = (p+q)\,/\,2 \text{ et  }  b = (p-q)\,/\,2.}}`$   
   $`\color{blue}{\scriptsize{ \quad\text{Nous retrouvons ainsi  }}}`$
-  $`\color{blue}{\scriptsize{ \quad\quad cos(p) + cos(q) = 2\,cos\Big(\dfrac{p+q}{2}\Big)\,cos\Big(\dfrac{p-q}{2}\Big)}}`$   
+  $`\color{blue}{\scriptsize{ \quad\quad cos(p) + cos(q) = 2\,cos\Big(\dfrac{p+q}{2}\Big)\,cos\Big(\dfrac{p-q}{2}\Big)}}`$ 
   <br>
-  $`\quad \begin{align}=A\;\Big[\,&c\alpha\cdot 2\,cos\Big(\dfrac{\varphi_1+\varphi_2}{2}\Big)\,cos\Big(\dfrac{\varphi_1-\varphi_2}{2}\Big)\\
-     &- s\alpha\cdot 2\,sin\Big(\dfrac{\varphi_1+\varphi_2}{2}\Big)\,sin\Big(\dfrac{\varphi_1-\varphi_2}{2}\Big)\end{align}`$
+  $`\color{blue}{\scriptsize{ \quad\text{De même nous retrouverions }}}`$   
+  $`\color{blue}{\scriptsize{ \quad\quad sin(p) + sin(q) = 2\,sin\Big(\dfrac{p+q}{2}\Big)\,cos\Big(\dfrac{p-q}{2}\Big)}}`$ 
+  <br>
+  $`\quad \begin{align}=A\;\Big[\,&c\alpha\cdot 2\,c\Big(\dfrac{\varphi_1+\varphi_2}{2}\Big)\,c\Big(\dfrac{\varphi_1-\varphi_2}{2}\Big)\\
+     &- s\alpha\cdot 2\,s\Big(\dfrac{\varphi_1+\varphi_2}{2}\Big)\,c\Big(\dfrac{\varphi_1-\varphi_2}{2}\Big)\end{align}`$   
+  <br>
+  $`\quad \begin{align}=2\,A\;&c\Big(\dfrac{\varphi_1-\varphi_2}{2}\Big)\\
+     &\times \Big[\,c\alpha\,c\Big(\dfrac{\varphi_1+\varphi_2}{2}\Big)-s\alpha\,s\Big(\dfrac{\varphi_1+\varphi_2}{2}\Big)\,\Big]\end{align)`$
+
+
+
+]
 
+\Big[\,&c\alpha\cdot 2\,cos\Big(\dfrac{\varphi_1+\varphi_2}{2}\Big)\,cos\Big(\dfrac{\varphi_1-\varphi_2}{2}\Big)\\
+     &- s\alpha\cdot 2\,sin\Big(\dfrac{\varphi_1+\varphi_2}{2}\Big)\,cos\Big(\dfrac{\varphi_1-\varphi_2}{2}\Big)\end{align}`$