Hi there. I have some doubts with this exercise. I have to make the summation for:
I've solved this way:
The doubt I've got is about the "negative" part of the summation, I know how to solve the geometric progression, but I'm not sure about the other part. I've proceeded this way:
This is what I did:
I'm not sure about this, may I should do it this other way?:
I mean, taking the values of the sequence for the series for every "i", and making that summation but the accumulation? cause I think it has not much sense what I did before, I mean there is no accumulation for the negative part, right?
Bye there, and thanks for your help.