Merge pull request jrjohansson#14 from kostyabazhanov/master

Fix misprints.

Author: jrjohansson

Lecture-1-Introduction-to-Python-Programming.ipynb

@@ -3018,7 +3018,7 @@
      "cell_type": "markdown",
      "metadata": {},
      "source": [
-      "This technique is useful for exmample when we want to pass a simple function as an argument to another function, like this:"
+      "This technique is useful for example when we want to pass a simple function as an argument to another function, like this:"
      ]
     },
     {
@@ -3128,7 +3128,7 @@
      "input": [
       "p1 = Point(0, 0) # this will invoke the __init__ method in the Point class\n",
       "\n",
-      "print(p1)         # this will invode the __str__ method"
+      "print(p1)         # this will invoke the __str__ method"
      ],
      "language": "python",
      "metadata": {},

Lecture-5-Sympy.ipynb

@@ -1126,7 +1126,7 @@
      "source": [
       "### Differentiation\n",
       "\n",
-      "Differentiation is usually simple. Use the `diff` function. The first argument is the expression to take the derivative of, and the second argument is the symbol by which to take the deriative:"
+      "Differentiation is usually simple. Use the `diff` function. The first argument is the expression to take the derivative of, and the second argument is the symbol by which to take the derivative:"
      ]
     },
     {