# A reasonning question

Hi ,
i have a question I dont know how to answer:

Explain why the potential integral formula cannot be used to directly determine the potential from an infinite uniform line charge ρlo that is on the z axis.

When we talk about it in class, I learn that the potential integral was used for finite displacement. I d read the textbook but I did not have other information.

So I there other reason to answer this question?

B.