Hi all,

With reference to the pdf in the link below second slide.
I can see that j[dX(e^jw)/dw] was taken from the DTFT property, but how was it changed to jd/dw[1/(1-e^-jw)] and than to [αe^-jw/(1-αe^-jw)] ??

http://www2.units.it/ramponi/teaching/DSP/materiale/Ch3(2).pdf

Any kind of help would be highly appreciated and sorry for my poor English.

 

Also, in slide 3 third bullet it is mentioned that δ[n-1] = e^-jw , but the property states that it is equal to δ(w)e^-jwn (please see attached diagram).
Is δ(w) not written down because it is an impulse, hence it is equal to 1? and in e^-jwn , n is not written down since it is equal to 1?

Thanks in advance.

 

Any help please?