function dydt = sensitive_deriv ( t, y )

%*****************************************************************************80
%
%% sensitive_deriv() evaluates the derivative of sensitive_ode().
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    03 December 2021
%
%  Author:
%
%    John Burkardt
%
%  Reference:
%
%    John D Cook,
%    Sensitive dependence on initial conditions in ODE's,
%    12 November 2013,
%    https://www.johndcook.com/blog/2013/11/12/sensitive-dependence-on-initial-conditions/
%
%  Input:
%
%    real T, Y: the arguments of the derivative.
%
%  Output:
%
%    real DYDT(2,1): the value of the derivative.
%
  dydt = zeros ( 2,1 );
  dydt(1,1) = y(2);
  dydt(2,1) = y(1);

  return
end
