diff --git a/advanced-math/exercise/3-derivative-and-differentiate/derivative-and-differentiate.tex b/advanced-math/exercise/3-derivative-and-differentiate/derivative-and-differentiate.tex
index ac3dd62..33fb8b6 100644
--- a/advanced-math/exercise/3-derivative-and-differentiate/derivative-and-differentiate.tex
+++ b/advanced-math/exercise/3-derivative-and-differentiate/derivative-and-differentiate.tex
@@ -315,4 +315,6 @@ $\therefore k=\dfrac{\dfrac{\sqrt{2}}{2}}{\dfrac{3}{2}\cdot\sqrt{\dfrac{3}{2}}}=
 
 当$2x-4=0$时即在$(2,7)$时曲率最大为2。
 
+
+
 \end{document}