Refactor code for improved readability and consistency across multiple Jupyter notebooks

- Added missing commas in various print statements and function calls for better syntax.
- Reformatted code to enhance clarity, including breaking long lines and aligning parameters.
- Updated function signatures to use float type for sigma parameters instead of int for better precision.
- Cleaned up comments and documentation strings for clarity and consistency.
- Ensured consistent formatting in plotting functions and data handling.

L3/Equations Différentielles/TP2_Lokta_Volterra.ipynb

@@ -125,7 +125,7 @@
     "        [\n",
     "            (C[0] * np.exp(-(t - t0)) * U1[0] + C[1] * np.exp(-2 * (t - t0)) * U2[0]),\n",
     "            (C[0] * np.exp(-(t - t0)) * U1[1] + C[1] * np.exp(-2 * (t - t0)) * U2[1]),\n",
-    "        ]\n",
+    "        ],\n",
     "    )\n",
     "\n",
     "\n",