First of all,thank you for your attention.
The exercise is very straightforward and it's easy to understand what is asking.
I basically have two functions. I calculated (correctly) the fourier transform of each one.
Now I need to sketch one period of the magnitude of each Fourier transform.
$$e^-j\omega * \frac{1}{1 - (1/2)e^-j\omega}$$
$$\frac{0.75e^-j\omega}{1.25-cos(\omega)}$$
Thanks once again,