Science Talk Science Talk    FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Forums Science Forums Biology Math Astronomy Physics Technology Chemistry Social Sciences History Psychology Philosophy Sociology Linguistics Religious Studies Economics Man Woman Ethno Ask an Expert World Records Society Issues Education People Alternative Science limit at the point of infinity          Science Talk Forum Index -> Mathematics View previous topic :: View next topic   Author Message Ying Guest Posted: Mon Jul 14, 2008 2:09 am    Post subject: limit at the point of infinity Dear all, Can someone answer the following question for me? If a real function f(x) from R to R converges to 0 as x goes to infinity, does f(z) goes to 0 as well when the complex variable goes to the point of infinity? Thanks a lot!! Ying Back to top   Ads Advertising Sponsor Raphanus Guest Posted: Mon Jul 14, 2008 3:20 am    Post subject: Re: limit at the point of infinity On Jul 13, 10:09 pm, Ying <yfan1...@yahoo.com.cn> wrote: Quote: Dear all, Can someone answer the following question for me? If a real function f(x) from R to R converges to 0 as x goes to infinity, does f(z) goes to 0 as well when the complex variable goes to the point of infinity? Thanks a lot!! Ying If I understand your question consider e^(-r) and e^(-ir) The first goes to zero as r goes to infinity; - the second one does not. Back to top   Ads Advertising Sponsor Virgil Guest Posted: Mon Jul 14, 2008 9:31 am    Post subject: Re: limit at the point of infinity In article <1655964.1216001413338.JavaMail.jakarta@nitrogen.mathforum.org>, Ying <yfan1980@yahoo.com.cn> wrote: Quote: Dear all, Can someone answer the following question for me? If a real function f(x) from R to R converges to 0 as x goes to infinity, does f(z) goes to 0 as well when the complex variable goes to the point of infinity? Thanks a lot!! Ying The "complex function" need not even be defined, and, even if defined, need not converge to 0 as |z| goes to infinity. Back to top   Ads Advertising Sponsor José Carlos Santos Guest Posted: Mon Jul 14, 2008 9:38 am    Post subject: Re: limit at the point of infinity On 14-07-2008 3:09, Ying wrote: Quote: Can someone answer the following question for me? If a real function f(x) from R to R converges to 0 as x goes to infinity, does f(z) goes to 0 as well when the complex variable goes to the point of infinity? No, not even when the statement makes sense and you are dealing with analytic functions alone. Take, for instance, the function _f_ such that f(0) = 1 and that f(x) = sin(x)/x otherwise. Best regards, Jose Carlos Santos Back to top   Ads Advertising Sponsor Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         Science Talk Forum Index -> Mathematics All times are GMT Page 1 of 1   Jump to: Select a forum Science Talk----------------Science TalkAstrologyNanotechnologySETISociology-- Elections-- LibertarianCreationismMathematicsPolitics  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Australian Debt Consolidation Experts medical insurance Wedding Websites Annunci di escort e accompagnatrici a Rimini, Padova, Treviso, in Riviera Adriatica, in Versilia ... Naughty British Wives Sex Contacts Point of Sale cheap loans Make Your Own Website Cheap calls to Saudi Arabia Cleaning Service Mold UK Swingers Genuine Contacts Site Janitorial Supplies bissell Vacuum parts 192 Attacks blocked Powered by phpBB © 2001, 2005 phpBB Group