diff --git a/Chapter 2-3 极限/根值判别法.md b/Chapter 2-3 极限/根值判别法.md
index 1119ac7..c4d157b 100644
--- a/Chapter 2-3 极限/根值判别法.md	
+++ b/Chapter 2-3 极限/根值判别法.md	
@@ -92,7 +92,7 @@ $ρ=\lim ⁡n→∞ u_n n ρ=n→∞\lim ​nu_n$​​
 
   
 
-ρ−ε<unn<ρ+ερ−ε<nun​​<ρ+ε
+$ρ−ε<unn<ρ+ερ−ε<nun​​<ρ+ε$