(a) Use Maxwells first equation, D = v, to describe the variation of the electric field intensity with x in a region in

(a) Use Maxwell’s first equation, ∇ · D = ρv, to describe the variation of the electric field intensity with x in a region in which no charge density exists and in which a nonhomogeneous dielectric has a permittivity that increases exponentially with x. The field has an x component only;

(b) Repeat part (a), but with a radially directed electric field (spherical coordinates), in which again ρ_v = 0, but in which the permittivity decreases exponentially with r.