Two infinitely long coaxial cylindrical surfaces, having cylindrical radii a and b respectively, where a < b, carry surface charge densities rsa and rsb respectively. (a) Find E everywhere (i.e., this means using Gauss's Law to obtain three algebraic expressions for E that can be used when the radius is less than the inner cylinder, or is between the two, or is outside the larger cylinder), and (b) What must be the relation between a and b in order that E = 0 at any point outside the larger cylinder of the two?