Bonjour!

I have a few math questions involving locating and classifying singularities for the following functions:

a) $\displaystyle f(z) = \frac{1}{1-e^{z^{2}}}$

b) $\displaystyle f(z) = \frac{z}{e^{\frac{1}{z}}}$

c) $\displaystyle f(z) = \frac{1-e^{z}}{z}$

Merci!