Two equal positive charges are on the axis; one point charge is at y = +a and the other is at y = -a.
(a) Show that on the x axis the x component of the electric field is given by Ex = 2kqx/(x2 + a2)3/2.
(b) Show that near the origin, where x is much smaller than a, Ex ˜ 2kqx/a3.
(c) Show that for values of x much larger than a, Ex ˜ 2kq/x2. Explain why a person might expect this result even without deriving it by taking the appropriate limit.
The more detail the better. If possible down the equations and thought into them as much as possible