A point charge +8. 00 nC is on the −x-axis at x = -0. 200 m, and a point charge -4. 00 nC is on the +x-axis at x = 0. 200 m. a) In addition to x=±[infinity], at what point on the x-axis is the resultant field of the two charges equal to zero? b) Let V=0 at x=±[infinity]. At what two other points on the x-axis is the total electric potential due to the two charges equal to zero? c) Is E=0 at either of the points in part B where V=0?