(a) Show that the normal component of electrostatic field has a discontinuity from one side of a charged surface to another given by

Where is a unit vector normal to themsurface at a point and σ is the surface charge density at that point. (The direction of n cap is from side 1 to side 2.) Hence show that just outside a conductor, the electric field is σ n cap/εo
(b) Show that the tangential component of electrostatic field is continuous from one side of a charged surface to another. [Hint: For (a), use Gauss’s law. For, (b) use the fact that work done by electrostatic field on a closed loop is zero.]