function fx = p15_fx ( n, x )

%*****************************************************************************80
%
%% P15_FX evaluates the function for problem 15.
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    10 October 2020
%
%  Author:
%
%    John Burkardt
%
%  Input:
%
%    integer N, the number of variables and equations.
%
%    real X(N), the evaluation point.
%
%  Output:
%
%    real FX(N), the function value.
%
  fx = zeros ( n, 1 );

  fx(1) = ( x(1) * x(1) + x(2) * x(3) ) - 0.0001;
  fx(2) = ( x(1) * x(2) + x(2) * x(4) ) - 1.0;
  fx(3) = ( x(3) * x(1) + x(4) * x(3) ) - 0.0;
  fx(4) = ( x(3) * x(2) + x(4) * x(4) ) - 0.0001;

  return
end

