diff --git a/src/nodes/parse.rs b/src/nodes/parse.rs
index 6da0edb..662871a 100644
--- a/src/nodes/parse.rs
+++ b/src/nodes/parse.rs
@@ -43,11 +43,11 @@ impl FromStr for Function {
             "ln" => Ok(Self::Ln),
 
             "sin" => Ok(Self::Sine),
-            "asin" => Ok(Self::ArcSine),
+            "asin" | "arcsin" => Ok(Self::ArcSine),
             "cos" => Ok(Self::Cosine),
-            "acos" => Ok(Self::ArcCosine),
+            "acos" | "arccos" => Ok(Self::ArcCosine),
             "tan" => Ok(Self::Tangent),
-            "atan" => Ok(Self::ArcTangent),
+            "atan" | "arctan" => Ok(Self::ArcTangent),
             "sec" => Ok(Self::Secant),
             "csc" => Ok(Self::CoSecant),
             _ => Err(s.to_owned()),