(a) Use Maxwell’s first equation, , to describe the variation of the electric field intens...

(a) Use Maxwell’s first equation, , 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 ρv = 0, but in which the permittivity decreases exponentially with r.