(*						      *)
(* Numerical Mathematics and Computing, Fifth Edition *)
(* Ward Cheney & David Kincaid		              *)
(* Brooks/Cole Publ. Co.			      *)
(* (c) 2004                                           *)
(* No warranties implied or expressed.	              *)
(* File: ode_high_order				      *)

(* solution system of high-order ODEs *)
NDSolve[{x''[t] == x[t] - y[t] - (3*x'[t])^2 + (y'[t])^3 + 6*y''[t] + 2*t,
         y'''[t] == x''[t] - x'[t] + Exp[x[t]] - t,
         x[1] == 2, x'[1] == -4, 
         y[1] == -2, y'[1] == 7, y''[1] == 6},
        {x, y}, {t, 1, 1.5}]
x[1.5] /. %
y[1.5] /. %%