// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

// @dart = 2.9

/// @assertion double atan(num x)
/// Returns a value in the range -PI/2..PI/2, or NaN if [x] is NaN.
/// @description Checks that [atan] returns NaN if [x] is NaN.
/// @author msyabro


import "dart:math" as Math;
import "../../Utils/expect.dart";

main() {
  Expect.isTrue(Math.atan(double.nan).isNaN);
}