diff --git a/classification/Neural Networks.ipynb b/classification/Neural Networks.ipynb
index f97a090e8b97235d5a6d9fde0d6c1f5fba4bc48a..7052c06a06546a09e6d5372e813d0562a510c5c2 100644
--- a/classification/Neural Networks.ipynb	
+++ b/classification/Neural Networks.ipynb	
@@ -148,7 +148,7 @@
     "\n",
     "- $dz_\\dagger^{(3)} = \\frac 1 m (h - y) $ (Error of the output layer)\n",
     "- $d\\theta_\\dagger^{(2)} = {a^{(2)}}^T dz_\\dagger^{(3)}$ (Gradient of $\\theta_2$)\n",
-    "- $d{a_\\dagger^{(2)}} = d\\theta_\\dagger^{(2)} {dz_\\dagger^{(3)}}^T$\n",
+    "- $d{a_\\dagger^{(2)}} = \\theta^{(2)} {dz_\\dagger^{(3)}}^T$\n",
     "- remove first row from $d{a_\\dagger^{(2)}}$\n",
     "- $dz_\\dagger^{(2)} = d{a_\\dagger^{(2)}} \\frac d {dz}\\sigma(z^{(2)}) $ (Error of the hidden layer)\n",
     "- $d\\theta_\\dagger^{(1)} = {a^{(1)}}^T dz_\\dagger^{(2)}$ (Gradient of $\\theta_1$)\n",