Classify three isolated singularities

Classify each indicated isolated singularity as removable, a pole, or essential; for a pole give its order:

1. \(\displaystyle \frac{(e^z-1)^3}{z^6}\) at \(z=0\);

2. \(\displaystyle \frac{\sin z}{z^2-\pi^2}\) at \(z=\pi\);

3. \(\displaystyle \frac{\cos(1/z)}{z^3}\) at \(z=0\).