On a regularization of index 2 differential-algebraic equations with properly stated leading term

In this article, linear regular index 2 DAEs A(t)[D(t)x(t)]'+B(t)x(t)=q(t) are considered. Using a decoupling technique, initial condition and boundary condition are properly formulated. Regular index 1 DAEs are obtained by a regularization method. We study the behavior of the solution of the regularization system via asymptotic expansions. The error analysis between the solutions of the DAEs and its regularization system is given.