Re: Multiple choice question

*To*: mathgroup at smc.vnet.net*Subject*: [mg26952] Re: Multiple choice question*From*: "A. Ciarkowski" <aciark at ippt.gov.pl>*Date*: Sat, 27 Jan 2001 20:00:16 -0500 (EST)*Organization*: http://news.icm.edu.pl/*References*: <943dj3$cjh@smc.vnet.net> <wq8a6.3201$nn4.99854@ralph.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Prof. J. Boersma from Eindhoven University of Technology has just sent me his remarks on proper analytic continuation of the Ei(x) function onto the complex z (= x + I y) plane. In view of these remarks, I must correct myself: the integral Integrate[ Exp[ I t 2 ]/(t - 1 - I), {t, 0, Infinity}] equals Exp[2 I - 2] ( Pi I - ExpIntegralEi[ 2 - 2 I] ), and hence the first result, Out[12], is correct. Adam