function [ fx, fy ] = f05_f1 ( n, x, y )

%*****************************************************************************80
%
%% F05_F1 returns first derivatives of function 5.
%
%  Licensing:
%
%    This code is distributed under the GNU LGPL license.
%
%  Modified:
%
%    29 January 2012
%
%  Author:
%
%    John Burkardt
%
%  Parameters:
%
%    Input, integer N, the number of evaluation points.
%
%    Input, real X(N,1), Y(N,1), the evalution points.
%
%    Output, real FX(N,1), FY(N,1), the derivative values.
%
  t1(1:n,1) = x(1:n,1) - 0.5;
  t2(1:n,1) = y(1:n,1) - 0.5;
  t3(1:n,1) = - 13.5 * exp ( - 20.25 * ( t1(1:n,1) .* t1(1:n,1) + t2(1:n,1) .* t2(1:n,1) ) );
  fx(1:n,1) = t1(1:n,1) .* t3(1:n,1);
  fy(1:n,1) = t2(1:n,1) .* t3(1:n,1);

  return
end