Classify three singularities and find their residues

For each function, classify the singularity at the indicated point and find the residue:

1. \(f(z)=z^2e^{-1/z^3}\) at \(z_0=0\);

2. \(f(z)=\dfrac{z^2}{(z-1)^2}\) at \(z_0=1\);

3. \(f(z)=\dfrac{\sin(z^3)}{(1-\cos z)^3}\) at \(z_0=0\).