Equations 22-8 and 22-9 are approximations of the magnitude of the electric field of an electric dipole, at points along the dipole axis. Consider a...

Equations 22-8 and 22-9 are approximations of the magnitude of the electric field of an electric dipole, at points along the dipole axis. Consider a point P on that axis at distance z = 7.00d from the dipole center(where d is the separation distance between the particles of the dipole). Let Eappr be the magnitude of the field at point P as approximated by Equations 22-8 and 22-9. Let Eact be the actual magnitude. By how much is the ratio Eappr/Eact less than 1?