Find the isolated singularities of the function $$f(z)=\frac{e^z-1}{z^4(z^2+4\pi^2)}$$ $$$$
I have done the following :
We set the denominator equal to zero : $$z^4(z^2+4\pi^2)=0 \Rightarrow z=0 \text{ or } z^2+4\pi^2=0 \Rightarrow z=\pm 2\pi i$$ These are the isolated singularities, right?