(cod: P-71-64-11) Determine the integrals below:

(1) \(\displaystyle \int x \cos{x} \, dx\)

(2) \(\displaystyle \int_0^{\frac{\pi}{2}}e^x \cos{x} \, dx\)

(3) \(\displaystyle \int_0^1 \arctan\, x \, dx\).