start expanding cost function

cw1/spce0038_coursework_sklearn_MCMQ7.ipynb

@@ -398,6 +398,7 @@
    ]
   },
   {
+   "attachments": {},
    "cell_type": "markdown",
    "metadata": {
     "deletable": false,
@@ -413,16 +414,13 @@
     }
    },
    "source": [
-    "YOUR ANSWER HERE"
+    "$$C(\\theta)=(X\\theta-y)^T(X\\theta-y)$$\n",
+    "$$(A+B)^T = A^T+B^T$$\n",
+    "$$\\therefore (X\\theta-y)^T=(X\\theta)^T-y^T$$\n",
+    "$$(AB)^T = A^TB^T$$\n",
+    "$$\\therefore (X\\theta)^T=X^T\\theta^T$$"
    ]
   },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
-   "source": []
-  },
   {
    "cell_type": "markdown",
    "metadata": {