function f2 = p13_f2 ( x )

%*****************************************************************************80
%
%% p13_f2() evaluates the second derivative for problem 13.
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    04 August 2019
%
%  Author:
%
%    John Burkardt
%
%  Input:
%
%    real x, the values of the variables.
%
%  Output:
%
%    real f2, the second derivative.
%
  f2 = 24.0 * x.^2 - 14.0;

  return
end
