function value = bill2_fp ( xy )

%*****************************************************************************80
%
%% bill2_fp evaluates the jacobian of the bill2 function.
%
%  Licensing:
%
%    This code is distributed under the GNU LGPL license.
%
%  Modified:
%
%    22 September 2019
%
%  Input:
%
%    real xy(2), the argument.
%
%  Output:
%
%    real value(2,2), the jacobian matrix.
%
  x = xy(1);
  y = xy(2);

  value = [ ...
    1.0,        -1.0+cos(y);
    3.0*cos(x), -1.0 ];


  return
end

