1. Find or derive an expression for a differential element of charge dq in spherical coordinates. [2] 2. Derive an expression for the rectangular components of the differential vector field dE at an arbitrary point in space r = (x, y, z) due to the differential element dq, located at a particular coordinate (R, θ, ϕ) on the surface of the sphere. That is, the expression should depend on these six quantities (plus k and Q), and should be in rectangular form, dE = (dEx, dEy, dEz), as this is the ONLY way to add up the contributions from every differential element of charge dq. [5]