diff --git a/main/math.tex b/main/math.tex
index ce25eee..1e1e552 100644
--- a/main/math.tex
+++ b/main/math.tex
@@ -35,5 +35,5 @@
 \newcommand{\lcm}{\text{lcm}}
 \newcommand{\limit}[2]{\lim_{#1 \rightarrow #2}}
 \DeclareMathOperator\arctanh{arctanh}
-\DeclareMathOperator\arccosh{arccosh}
+\DeclareMathOperator\arcosh{arcosh}
 \DeclareMathOperator\arcsinh{arcsinh}