add items to "what we've learned"

Author: labarba

Diff for: notebooks_en/1_Linear_Regression.ipynb

@@ -467,7 +467,9 @@
     "- Linear regression starts by assuming a linear relationship between two variables.\n",
     "- A model includes the assumed relationship in the data and model parameters.\n",
     "- Observational data allows finding the parameters in the model (slope, intercept).\n",
-    "- SymPy computes derivatives with `sympy.diff()` and returns numeric functions with `simpy.lambdify()(`."
+    "- A loss function captures the deviation between the observed and the predicted values of the dependent variable.\n",
+    "- We find the parameters by minimizing the loss function via gradient descent.\n",
+    "- SymPy computes derivatives with `sympy.diff()` and returns numeric functions with `simpy.lambdify()`."
    ]
   },
   {
@@ -670,7 +672,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.6.13"
+   "version": "3.8.5"
   }
  },
  "nbformat": 4,