diff --git a/Notebooks/Chap06/6_4_Momentum.ipynb b/Notebooks/Chap06/6_4_Momentum.ipynb
index 87cce41..40f5a65 100644
--- a/Notebooks/Chap06/6_4_Momentum.ipynb
+++ b/Notebooks/Chap06/6_4_Momentum.ipynb
@@ -123,7 +123,7 @@
     {
       "cell_type": "code",
       "source": [
-        "# Initialize the parmaeters and draw the model\n",
+        "# Initialize the parameters and draw the model\n",
         "phi = np.zeros((2,1))\n",
         "phi[0] =  -5     # Horizontal offset\n",
         "phi[1] =  25     # Frequency\n",