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.

M1/Numerical Methods/TP1.ipynb

@@ -338,7 +338,7 @@
     "    return np.max(\n",
     "        np.power(np.abs(sol_appr - sol_exact), 2)[\n",
     "            np.isfinite(np.power(np.abs(sol_appr - sol_exact), 2))\n",
-    "        ]\n",
+    "        ],\n",
     "    )\n",
     "\n",
     "\n",