SHOW ALL WORK; Including Variable Equation and Supporting work.

A non conducting flat ring of inner radius a and outer radius b lies centered on the y z plane (A disk with a hole in the center). It has a uniform surface charge density sigma (o). Be sure your answers are only in terms of what variables are given. a) Find an equation for the electric field at a distance x from the center along the x axis (perpendicular to the disk's plane). If something is zero be sure to show or explain why. b) Find an equation for the electric potential at that same point from the disk.