function exact = p04_exact ( )

%*****************************************************************************80
%
%% p04_exact() returns the exact integral for problem 4.
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    31 July 2007
%
%  Author:
%
%    John Burkardt
%
%  Output:
%
%    real EXACT, the value of the integral.
%
  exact = sqrt ( pi / 2.0 );

  return
end
