1. The problem statement, all variables and given/known data Approximate an infinite field of charge as a sheet of infinitely long charged wires each with charge dQ = λL . Use the formula for the electric field of a wire in the limit as L goes to infinity to derive the formula for an infinite sheet of charge dencity η. You need to express λ in terms of of the surface charge density η times an infinetismall distance. 2. Relevant equations E of infinite line charge = λ/(4 π e0 r) integral of x/(x^2+y^2) dy = arctan (y/x) 3. The attempt at a solution Wow... I don't even know where to start I'll assume the wires run parallel to the y-axis then the area of each wire is L*dx (assumign dy is the thickness of each wire η = Q / A Now the area of each wire is L*dx , and since the charge of each is dQ η = dQ / L*dx = λL/L*dx = λ/dx honestly I have no idea what else to do or if there was even a point to doing what i just did...help!