Question

drive expression for electric field due to dipole on axial and equatorial point​

Answer 1

Let P be a point on the axial line of the dipole. Let the distance of point P from the midpoint of the dipole be r such that r>>>a. The electric field at point P will be due to the two charges on the given dipole. The magnitude of electric field due to the charge +q will be E+q=kq(r−a)2.