1. The problem statement, all variables and given/known data See figure attached. 2. Relevant equations 3. The attempt at a solution See figure attached. I'm confused how they deduced that V1-V2 is going to be the integral of the electric field from a to b. How do they choose the path from a to b? How can they say that the electric field integrated over this path is going to be V1-V2? I express the same confusion over the 2nd integral, why is V2 equal to the electric field integrated from c to d?