Three identical point charges each of charge q are located at the vertices of an equilateral triangle. The distance from the center of the triangle to each vertex is a.
(a) Show that the electric field at the center of the triangle is zero.
(b) Find a symbolic expression for the electric potential at the center of the triangle.
(c) Give a physical explanation of the fact that the electric potential is not zero, yet the electric field is zero at the center.