function f = p28_f ( x )

%*****************************************************************************80
%
%% p28_f() evaluates the objective function for test 28.
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    23 February 2026
%
%  Author:
%
%    John Burkardt
%
%  Input:
%
%    real x: the argument.
%
%  Output:
%
%    real f: the function value.
%
  f = 12.2 + 10.0 * sin ( 19.0 * x - 2.0 );

  return
end
