update Ch03-3

Author: rambasnet

Ch03-3-Functions-UserDefined.ipynb

@@ -15,7 +15,7 @@
     "    # STATEMENTS\n",
     "    return VALUE\n",
     "```\n",
-    "- PARAMETERS AND return statements are OPTIONAL\n",
+    "- PARAMETERS and return statements are OPTIONAL\n",
     "- function NAME follows the same rules as a variable/identifier name\n",
     "- some built-in functions and object methods have been used..."
    ]
@@ -36,7 +36,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "## Two-step process\n",
+    "## two-step process\n",
     "1. define function\n",
     "- call/use function"
    ]
@@ -309,7 +309,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### visualize variables' scope using pythontutor:\n",
+    "### visualize variables' scope using pythontutor\n",
     "https://goo.gl/TyXPg6"
    ]
   },