1. The problem statement, all variables and given/known data I don't understand the follow formula of the integral : Integral of ( E dot dL) from B to A What direction is the dr vector? Is it the direction of the line integral? Say I want to derive the formula for electric potential due to a point in Space. E has a direction vector of ar assume dL is pointing from infinity to A (-ar), which is opposite of the Eletric Field. And the formula ends up with a negative sign, which is not consistent with the formal formula. Why?