How to simplify SUM(k=0,inf,x^k/k!) ?



#2

Hi

I'm playing around with various CAS implementations and found that it's no so easy to find the simplification for the well known infinite sum:

 oo
----'
\ xk
| ---
/ k!
----'
k=0
Is this possible with the 49g+ or any other Erable based CAS?

The Voyage 200 does not do it, while Derive on the PC knows the correct result.

Marcus


#3

I don't think the 49G+ can do it.

It can at least find sum(n = 1, inf, 1/n^x) for even x.

And it can find various closed forms of finite sums (the geometric series, 1 + 2 + 3 + ... + n = n(n+1)/2, sums of reciprocal triangle numbers, more complicated cases), too.


Possibly Related Threads...
Thread Author Replies Views Last Post
  Prime: sum-of Paul D. Fox 2 302 10-13-2013, 10:22 AM
Last Post: Tim Wessman
  Simplify with sci/eng on hp 50g Juraj O. 11 831 11-08-2012, 06:26 PM
Last Post: Han
  SUM function on WP-34S Thomas Scott 11 729 04-18-2012, 06:10 PM
Last Post: fhub
  41CX-MCODE: Digit Sum function Ángel Martin 17 1,079 12-09-2011, 08:06 AM
Last Post: Ángel Martin
  34S SUM PROD change request ccccc >= fff Egan Ford 6 587 10-02-2011, 08:06 AM
Last Post: Marcus von Cube, Germany
  sum of the first n integers Gerson W. Barbosa 18 1,025 06-01-2010, 07:19 PM
Last Post: Gerson W. Barbosa
  Bug in SIMPLIFY? (hp 50g) Luca 6 462 08-20-2009, 05:03 PM
Last Post: Nigel J Dowrick
  How to prevent automatic substitution during SIMPLIFY Luca 2 221 08-17-2009, 02:48 AM
Last Post: Luca
  sum list in 17bii solver equation Don Shepherd 8 602 08-14-2007, 03:13 PM
Last Post: Don Shepherd
  17bii+ bug update and Sum-Of-Digits Bruce Bergman 1 197 02-26-2007, 12:22 AM
Last Post: Bruce Bergman

Forum Jump: