A slow proton beam fills the space between two large parallel metal plates. The distance between the plates is 2a. One plate at x=-a is grounded and the other plate at x=a is connected to a source at electric potential V(0). The charge density of the proton beam is p=p(0)cos[pi*x)/(2a)] where p(0) is a constant.
Find the electric and potential field between the plates. Here the motion of the proton beam can be ignored.