Update cheatsheet.fr.md

12.temporary_ins/04-math-tools/70.systems-of-differential-equations/40.parallel-1/cheatsheet.fr.md

@@ -92,7 +92,13 @@ $`\begin{align} \quad\;\; & = \;\dfrac{1}{0!}\;\begin{pmatrix} 1 & 0 & 0 \\ 0 &
 \end{align}`$    
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-$`\quad\;\; = \;\begin{pmatrix} \dfrac{1}{n!}\sum_{n=0}^{+\infty}\,\lambda_1^n & 0 & 0 \\ 0 & \ddots & 0 \\ 0 & 0 & \dfrac{1}{n!}\sum_{n=0}^{+\infty}\,\lambda_m^n \\ \end{pmatrix}`$
+$`\displaystyle\quad\;\; = \;\begin{pmatrix} \dfrac{1}{n!}\sum_{n=0}^{+\infty}\,\lambda_1^n & 0 & 0 \\ 0 & \ddots & 0 \\ 0 & 0 & \dfrac{1}{n!}\sum_{n=0}^{+\infty}\,\lambda_m^n \\ \end{pmatrix}`$   
+<br>
+<br>
+**$`\mathbf{\quad\;\; = \;\begin{pmatrix} e^{\,\lambda_1} & 0 & 0 \\ 0 & \ddots & 0 \\ 0 & 0 & e^{\lambda_m} \\ \end{pmatrix}}`$**   
+
+
+##### $`M`$ est non diagonale, mais diagonalisable :