At $z = 0$ the function $f(z)=(e^z+1)/(e^z-1)$ has
1. A removable singularity
2. A pole
3. An essential singularity
4. The residue of $f (z )$ at $z = 0$ is $2$.
i am completely stuck on it.please help somebody.thanks.
At $z = 0$ the function $f(z)=(e^z+1)/(e^z-1)$ has
1. A removable singularity
2. A pole
3. An essential singularity
4. The residue of $f (z )$ at $z = 0$ is $2$.
i am completely stuck on it.please help somebody.thanks.