I have been staring at this problem for an hour. I am not even sure where to start. A thin, circular disk of radius R is oriented in the xy-plane with its center at the origin. A charge Q on the disk is distributed uniformly over the surface. (a.) Find the electric field due to the disk at the point z=z0 along the z-axis. (b.) Find the field in the limit z0 approached infinity. (c.) Find the field in the limit that R approaches infinity. Are the limits of parts (b) and (c) the same? I think that the electric field due to the disk = [(Q/area)*k]*integration of the change of something over the distance squared...I am just not seeing it in simple terms...Can someone point me in the right direction?