Omnimaga

General Discussion => Other Discussions => Math and Science => Topic started by: AngelFish on September 23, 2011, 04:42:55 am

Title: A simple problem
Post by: AngelFish on September 23, 2011, 04:42:55 am

Here's a little problem I noticed today that's quite easy for humans to solve, but is surprisingly difficult to get from a computer.

Lim_N→∞ e^-XN = f(x)

The challenge is to get a computer system to properly determine f(x) [after you solve it for yourself first].

Spoiler For Symbolic answer for humans:

It's the Boxcar function (http://mathworld.wolfram.com/BoxcarFunction.html) with limits of (-1,1).

Title: Re: A simple problem
Post by: phenomist on September 23, 2011, 07:32:14 pm

Also note that f(1)=e :P

Title: Re: A simple problem
Post by: sqrt(Time) on September 24, 2011, 12:41:07 pm

Wouldn't f(x) be undefined for any x>=1? As you take it to successive powers, it alternates wildly between negative infinity and positive infinity (or at least negative one and positive one), so the limit wouldn't exist.. or am I missing something? :-/