Problem 1604 (difficulty: 4/10)

\(\displaystyle \frac1{2\pi i}\int_{|z|=5}\frac{\cos z}z\dz = ? \qquad \int_{|z|=3}\frac{e^z}z\dz = ? \qquad \int_{|z|=3}\frac{e^z}{z-2}\dz = ? \qquad \int_{|z|=3}\frac{e^z}{(z-2)(z-4)}\dz = ? \)

Give me another random problem!