Check Stoke's theorem for the vector function

using the triangular surface shown in Figure 1. Express all your answers
in terms of *a*.

A spherical shell of radius

Consider the following three vector functions:

(1)

(2)

(3)

where

a) Which of these three vector functions can describe an electrostatic field?

b) For the vector function of part a) that can describe an electrostatic field find the corresponding electrostatic potential at point

c) Find the charge distribution that produces the electrostatic potential obtained in part b).

Express all your answers in terms of