# Thread: Z - transform 1/z-1

1. ## Z - transform 1/z-1

Hallo,

i would like o ask you one question.
I have a little question from this theard
is there an inverse Z transform for: 1/z-1 ?

i have a model in matlab and i am using discrete transfer fcn. it using z-transfor with this form 1/z-1 . at input are numbers and at output is one number that is a simple sum of inputs..for example inputs are 1, 2 , 3 and the output of this function is 6 .. everything is fine but i dont know how this fcn calculate it.

i think the sequence will be like this: 1*1^(-1) + 2*1^(-2) + 3*1^(-3) = 6 but im not sure its correct. can by the "z"=1? or what exactly is this "z" mean in this formula or in the sum.

thank you very much. i hope its easy but i realy wondering about it a lot.

2. ## Re: Z - transform 1/z-1

I have found a document in which is this :

so my question is can be the "z" = 1 ? or no. if yes then my sample above is correct? plz help me i dont kow much about this math.