# Converge of Complex Function

1. May 18, 2005

### heman

Hi,
In this Problem i am finding Problem to calculate the set of z:
Pls help
Determine all z $$\subset$$ C for which the following series is absolutely convergent:

$$\sum (1/n!)(1/z)^n$$

Thx

2. May 19, 2005

### Galileo

Do the terms look familiar? What if you set $w=\frac{1}{z}$?

3. May 19, 2005

### heman

okay ...but generally how to solve such kind of problems..can u be more logical pls

4. May 19, 2005

### matt grime

Use the ratio test (and i don't think you should accuse others of not being logical. pointing out that this is the series for exp{1/z} give or take a constant is very logical. you ought to put in the limits too).

5. May 19, 2005

### heman

its just my concepts are not clear....how can i accuse anyone here..i have learned a lot from ppl here and i wanna improve
Sometimes even in my class i end up asking such stupid questions that whole class bursts into laughter..
Thx for it and urs reply in pm...