diff --git a/Lectures_my/NumMet/2016/Lecture4/lecture4.tex b/Lectures_my/NumMet/2016/Lecture4/lecture4.tex
index 7893275..096f7ce 100644
--- a/Lectures_my/NumMet/2016/Lecture4/lecture4.tex
+++ b/Lectures_my/NumMet/2016/Lecture4/lecture4.tex
@@ -344,7 +344,7 @@
             axis y line=center,
             ymin=-0.1,ymax=0.9,
             xmin=-0.7,xmax=0.7,
-            title=$\sqrt(|x|)$,
+            title=$\sqrt{|x|}$,
             samples=160
         ]
             \addplot[thick,black,domain=-1:+0] {