Update cheatsheet.fr.md

12.temporary_ins/07.geometry-coordinates-prop2/40.n4/20.overview/cheatsheet.fr.md

@@ -1017,7 +1017,11 @@ _{\color{blue}{=\,\Gamma_{ab}^{\;c}\,\mathbf{e_c}}}
 \,\dfrac{dx^b}{d\lambda}\\
 \\
 &=\dfrac{dv^a}{d\lambda}\,\mathbf{e_a}+\underbrace{v^a\,\dfrac{dx^b}{d\lambda}\,\Gamma_{ab}^{\;c}\,\mathbf{e_c}}
-_{\color{blue}{\begin{array}{c}\text{a, b et c muets} \,\Longrightarrow \\ \text{interchangeables}\end{array}}}
+_{\color{blue}{\begin{array}{c}\text{a, b et c muets} \,\Longrightarrow \\ \text{interchangeables}\end{array}}}\\
+\\
+&=\dfrac{dv^a}{d\lambda}\,\mathbf{e_a}+\Gamma_{bc}^{\;a}\,\dfrac{dx^b}{d\lambda}\,v^c\,\mathbf{e_a}\\
+\\
+&=\letf(\dfrac{dv^a}{d\lambda}\,+\,\Gamma_{bc}^{\;a}\,\dfrac{dx^b}{d\lambda}\,v^c\right)\,\mathbf{e_a}
 \end{align}`$