function f = p18_f ( x )

%*****************************************************************************80
%
%% p18_f() evaluates the objective function for test 18.
%
%  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 = 1.2 + 3.0 * cosh ( x - 2.0 ) - 2.0 * sinh ( x - 3.0 );

  return
end

