What is the electric field at a point on equitorial line of an electric dipole?

kp/(r2 + a2)3/2 kp/2(r2 + a2)3/2 2kp/(r2 + a2)3/2 kp/4(r2 + a2)3/2

kp/(r2 + a2)3/2

The expression for electric field at a point on equitorial line of an electric dipole : E = kp/(r2 + a2)3/2