Singularity

[mkbh_10]

1. The problem statement, all variables and given/known data

Identify the singularity of f(z)= 1-e^z/1+e^z at z= infinity


2. Relevant equations



3. The attempt at a solution

How shud i start

[CompuChip]

You can convert the singularity at infinity to one at zero by considering
g(z) = f(1 / z)
Then apply the same strategy as here (http://www.physicsforums.com/showthread.php?t=223548)