A certain electric dipole consists of charges +q and -q separated by distance d, oriented along the x-axis as shown in the figure. Find an expression for the magnitude of the electric field E of the dipole at a point far away in the y-direction, a distance r away from the midpoint of the dipole. Assume that r is much greater than d. Enter your answer in terms of q, d, r, and ε0.
E =