(*						      *)
(* Numerical Mathematics and Computing, Fifth Edition *)
(* Ward Cheney & David Kincaid		              *)
(* Brooks/Cole Publ. Co.			      *)
(* (c) 2003                                           *)
(* No warranties implied or expressed.	              *)
(* File: error_integral2			      *)

(* numerical approximation of error function *)
N[0.5*Sqrt[Pi]*Erf[1.], 10]
N[NIntegrate[Exp[-x*x], {x,0,1}], 10]