diff --git a/5_nn/3-softmax_ce.ipynb b/5_nn/3-softmax_ce.ipynb
index f222841..8e5a1d1 100644
--- a/5_nn/3-softmax_ce.ipynb
+++ b/5_nn/3-softmax_ce.ipynb
@@ -78,12 +78,12 @@
     "神经元的输出设为：\n",
     "\n",
     "$$\n",
-    "z_i = sigmoid( \\sum_{j} w_{ij} x_{j} + b )\n",
+    "z_i = \\sum_{j} w_{ij} x_{j} + w_b\n",
     "$$\n",
     "\n",
-    "其中$W_{ij}$是第$i$个神经元的第$j$个权重，$b$是偏置。$z_i$表示该网络的第$i$个输出。\n",
+    "其中$W_{ij}$是第$i$个神经元的第$j$个权重，$w_b$是偏置。$z_i$表示该网络的第$i$个输出。**请注意这里没有使用sigmoid等激活函数。**\n",
     "\n",
-    "给这个输出加上一个softmax函数，那就变成了这样：\n",
+    "给这个网络输出加上一个softmax函数，那就变成了这样：\n",
     "\n",
     "$$\n",
     "a_i = \\frac{e^{z_i}}{\\sum_k e^{z_k}}\n",
@@ -211,7 +211,7 @@
     "\n",
     "其中\n",
     "$$\n",
-    "z_i = \\sum_{j} w_{ij} x_{j} + b\n",
+    "z_i = \\sum_{j} w_{ij} x_{j} + w_b\n",
     "$$\n"
    ]
   },
@@ -219,7 +219,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "对于使用二次代价函数的更新方程为：\n",
+    "最为对比，使用二次代价函数的更新方程为：\n",
     "\n",
     "$$\n",
     "\\delta_i = a_i (1-a_i) (y_i - a_i)\n",
diff --git a/5_nn/images/figures.pptx b/5_nn/images/figures.pptx
index 3ef4dde..a16b029 100644
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diff --git a/5_nn/images/softmax_neuron.png b/5_nn/images/softmax_neuron.png
index f9e736e..da10ee4 100644
Binary files a/5_nn/images/softmax_neuron.png and b/5_nn/images/softmax_neuron.png differ