I am having trouble understanding when a function might have a removable singularity over a pole.
For example:
$$f(z)=\frac{\sin^2 z}{z}$$
I believe the pole is at $z=0$. However, if we take the taylor expansion of $f(z)$ apparently the pole vanishes. I do not understand how and where does the pole vanish that it becomes a removable singularity.
Best Answer
$$\lim_{z \to 0}(z-0)\cdot f(z) =0$$ hence $0$ is removable singularity
this link may provide more clarity http://en.wikipedia.org/wiki/Removable_singularity