817. 1 Electrical potential energy and electric potential XThe first method of calculating the electric potential V-V=「E·dF Path Field line dr 817.2 The calculation of the electric potential 1. The electric potential of a pointlike charge q Edr rdr= )=V-V teo r4 ∫ − = ⋅ f i V V E dr i f r r r r d ※The first method of calculating the electric potential §17.1 Electrical potential energy and electric potential §17.2 The calculation of the electric potential 1. The electric potential of a pointlike charge Q P r ir q E r r r d i f i f r r V V r r Q r r r Q E r f i ⋅ = ⋅ = − = − ∫ ∫ ) 1 1 ( 4 ˆ d 4 d 0 2 0 f i πε πε r r r