diff --git a/datafusion/physical-expr/src/lib.rs b/datafusion/physical-expr/src/lib.rs
index 46185712413ef..e7c2b4119c5ae 100644
--- a/datafusion/physical-expr/src/lib.rs
+++ b/datafusion/physical-expr/src/lib.rs
@@ -27,7 +27,6 @@ pub mod binary_map {
 pub mod equivalence;
 pub mod expressions;
 pub mod intervals;
-pub mod math_expressions;
 mod partitioning;
 mod physical_expr;
 pub mod planner;
diff --git a/datafusion/physical-expr/src/math_expressions.rs b/datafusion/physical-expr/src/math_expressions.rs
deleted file mode 100644
index 503565b1e2613..0000000000000
--- a/datafusion/physical-expr/src/math_expressions.rs
+++ /dev/null
@@ -1,126 +0,0 @@
-// Licensed to the Apache Software Foundation (ASF) under one
-// or more contributor license agreements.  See the NOTICE file
-// distributed with this work for additional information
-// regarding copyright ownership.  The ASF licenses this file
-// to you under the Apache License, Version 2.0 (the
-// "License"); you may not use this file except in compliance
-// with the License.  You may obtain a copy of the License at
-//
-//   http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing,
-// software distributed under the License is distributed on an
-// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
-// KIND, either express or implied.  See the License for the
-// specific language governing permissions and limitations
-// under the License.
-
-//! Math expressions
-
-use std::any::type_name;
-use std::sync::Arc;
-
-use arrow::array::ArrayRef;
-use arrow::array::{BooleanArray, Float32Array, Float64Array};
-use arrow::datatypes::DataType;
-use arrow_array::Array;
-
-use datafusion_common::exec_err;
-use datafusion_common::{DataFusionError, Result};
-
-macro_rules! downcast_arg {
-    ($ARG:expr, $NAME:expr, $ARRAY_TYPE:ident) => {{
-        $ARG.as_any().downcast_ref::<$ARRAY_TYPE>().ok_or_else(|| {
-            DataFusionError::Internal(format!(
-                "could not cast {} from {} to {}",
-                $NAME,
-                $ARG.data_type(),
-                type_name::<$ARRAY_TYPE>()
-            ))
-        })?
-    }};
-}
-
-macro_rules! make_function_scalar_inputs_return_type {
-    ($ARG: expr, $NAME:expr, $ARGS_TYPE:ident, $RETURN_TYPE:ident, $FUNC: block) => {{
-        let arg = downcast_arg!($ARG, $NAME, $ARGS_TYPE);
-
-        arg.iter()
-            .map(|a| match a {
-                Some(a) => Some($FUNC(a)),
-                _ => None,
-            })
-            .collect::<$RETURN_TYPE>()
-    }};
-}
-
-/// Isnan SQL function
-pub fn isnan(args: &[ArrayRef]) -> Result<ArrayRef> {
-    match args[0].data_type() {
-        DataType::Float64 => Ok(Arc::new(make_function_scalar_inputs_return_type!(
-            &args[0],
-            "x",
-            Float64Array,
-            BooleanArray,
-            { f64::is_nan }
-        )) as ArrayRef),
-
-        DataType::Float32 => Ok(Arc::new(make_function_scalar_inputs_return_type!(
-            &args[0],
-            "x",
-            Float32Array,
-            BooleanArray,
-            { f32::is_nan }
-        )) as ArrayRef),
-
-        other => exec_err!("Unsupported data type {other:?} for function isnan"),
-    }
-}
-
-#[cfg(test)]
-mod tests {
-
-    use datafusion_common::cast::as_boolean_array;
-
-    use super::*;
-
-    #[test]
-    fn test_isnan_f64() {
-        let args: Vec<ArrayRef> = vec![Arc::new(Float64Array::from(vec![
-            1.0,
-            f64::NAN,
-            3.0,
-            -f64::NAN,
-        ]))];
-
-        let result = isnan(&args).expect("failed to initialize function isnan");
-        let booleans =
-            as_boolean_array(&result).expect("failed to initialize function isnan");
-
-        assert_eq!(booleans.len(), 4);
-        assert!(!booleans.value(0));
-        assert!(booleans.value(1));
-        assert!(!booleans.value(2));
-        assert!(booleans.value(3));
-    }
-
-    #[test]
-    fn test_isnan_f32() {
-        let args: Vec<ArrayRef> = vec![Arc::new(Float32Array::from(vec![
-            1.0,
-            f32::NAN,
-            3.0,
-            f32::NAN,
-        ]))];
-
-        let result = isnan(&args).expect("failed to initialize function isnan");
-        let booleans =
-            as_boolean_array(&result).expect("failed to initialize function isnan");
-
-        assert_eq!(booleans.len(), 4);
-        assert!(!booleans.value(0));
-        assert!(booleans.value(1));
-        assert!(!booleans.value(2));
-        assert!(booleans.value(3));
-    }
-}
diff --git a/datafusion/sqllogictest/test_files/math.slt b/datafusion/sqllogictest/test_files/math.slt
index eece569423177..1bc972a3e37da 100644
--- a/datafusion/sqllogictest/test_files/math.slt
+++ b/datafusion/sqllogictest/test_files/math.slt
@@ -102,7 +102,12 @@ SELECT nanvl(asin(10), 1.0), nanvl(1.0, 2.0), nanvl(asin(10), asin(10))
 
 # isnan
 query BBBB
-SELECT isnan(1.0), isnan('NaN'::DOUBLE), isnan(-'NaN'::DOUBLE), isnan(NULL)
+SELECT isnan(1.0::DOUBLE), isnan('NaN'::DOUBLE), isnan(-'NaN'::DOUBLE), isnan(NULL)
+----
+false true true NULL
+
+query BBBB
+SELECT isnan(1.0::FLOAT), isnan('NaN'::FLOAT), isnan(-'NaN'::FLOAT), isnan(NULL::FLOAT)
 ----
 false true true NULL