diff --git a/Study/DL/吴恩达深度学习课程/Lesson 1.md b/Study/DL/吴恩达深度学习课程/Lesson 1.md
index c5eea42..4c6b912 100644
--- a/Study/DL/吴恩达深度学习课程/Lesson 1.md	
+++ b/Study/DL/吴恩达深度学习课程/Lesson 1.md	
@@ -1 +1,10 @@
 # Neural Network and Deep Learning
+## Logistic Regression
+$$\begin{align}
+正向传递\\
+z &= w^Tx + b \\
+a &= \sigma(z) \\
+\hat{y} &= L(a) = -ylog(\hat{y}) - (1-y)log(1-\hat{y}) \ \ 其中(\hat{y} = a) \\
+反向传递 \\
+\frac{dL}{da}
+\end{align}$$