diff --git a/scripts/omml_mathml2latex/visitors/mrow_visitor.py b/scripts/omml_mathml2latex/visitors/mrow_visitor.py
index 52946eb..11e56d9 100644
--- a/scripts/omml_mathml2latex/visitors/mrow_visitor.py
+++ b/scripts/omml_mathml2latex/visitors/mrow_visitor.py
@@ -546,14 +546,28 @@ class MrowVisitor(Visitor):
         if len(letters) < 2:
             return ("", 0, None)
 
-        # Check if the sequence forms a known function
+        # Check if the sequence forms a known function.
+        # Use prefix matching so that "sinx" resolves to "sin" (leaving the
+        # trailing "x" for the caller to convert), rather than requiring the
+        # whole run to be a function name. Mirrors the logic in
+        # legacy_adapter._check_fragmented_function_at_level.
         from ..data import MATH_FUNCTIONS
-        potential_function = ''.join(letters)
+        potential_function = ""
+        matched_length = 0
+        for length in range(min(len(letters), 6), 1, -1):
+            candidate = ''.join(letters[:length])
+            if candidate in MATH_FUNCTIONS:
+                potential_function = candidate
+                matched_length = length
+                break
 
-
-        if potential_function not in MATH_FUNCTIONS:
+        if not potential_function:
             return ("", 0, None)
 
+        # Only the matched letters belong to the function; any trailing letters
+        # (e.g. the "x" in "sinx") remain for the caller to convert.
+        consumed_count = matched_length
+
         # Build the function LaTeX
         function_latex = f"\\{potential_function}"