Found small typos in the notebook

python_by_example.ipynb

@@ -824,7 +824,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "Set $ T=200 $ and $ \\alpha = 0.9 $."
+    "Set $ T=200 $ and $ \alpha = 0.9 $."
    ]
   },
   {
@@ -833,16 +833,16 @@
    "source": [
     "### Exercise 2\n",
     "\n",
-    "Starting with your solution to exercise 2, plot three simulated time series,\n",
-    "one for each of the cases $ \\alpha=0 $, $ \\alpha=0.8 $ and $ \\alpha=0.98 $.\n",
+    "Starting with your solution to exercise 1, plot three simulated time series,\n",
+    "one for each of the cases $ \alpha=0 $, $ \alpha=0.8 $ and $ \alpha=0.98 $.\n",
     "\n",
-    "Use a `for` loop to step through the $ \\alpha $ values.\n",
+    "Use a `for` loop to step through the $ \alpha $ values.\n",
     "\n",
     "If you can, add a legend, to help distinguish between the three time series.\n",
     "\n",
     "Hints:\n",
     "\n",
-    "- If you call the `plot()` function multiple times before calling `show()`, all of the lines you produce will end up on the same figure.  \n",
+    "- If you call `plot()` function multiple times before calling `show()`, all of the lines you produce will end up on the same figure.  \n",
     "- For the legend, noted that the expression `'foo' + str(42)` evaluates to `'foo42'`.  "
    ]
   },
@@ -1168,4 +1168,4 @@
  },
  "nbformat": 4,
  "nbformat_minor": 4
-}
+}