diff --git a/CH01/CH01_SEC03_Rotation.ipynb b/CH01/CH01_SEC03_Rotation.ipynb
index 110deca..43229d3 100644
--- a/CH01/CH01_SEC03_Rotation.ipynb
+++ b/CH01/CH01_SEC03_Rotation.ipynb
@@ -31,7 +31,9 @@
     "               [0, 0, 1]])\n",
     "\n",
     "# Rotate and scale\n",
-    "X = Rz @ Ry @ Rx @ Sigma"
+    "X = Rz @ Ry @ Rx @ Sigma\n", 
+    "# U, S, Vt = np.linalg.svd(X, full_matrices=False)\n",
+    "# X = U @ np.diag(S)"
    ]
   },
   {