Now let us produce similar graphs (both types) for the
electric potential for the case with two particles, one having
the original charge, the other having the opposite charge.
The first one is positioned 3.1 cm to the left of the origin
and the other 3.1 cm right of the origin.
(We have to move our charges off the grid for technical
reasons.)
The Minimum should be changed from 0 to -10 for these graphs.