1. Problem Statement. Find the Electrostatic Field at a distance z above the xy-plane and along the z-axis due to a constant surface charge σ confined to the region a < √(x2+y2) < b, 0 < α < pi/2. In other words, find the Electric Field a distance z above a quarter disk occupying the region between the positive x and y axes from r = a to r = b. 2. Known Equations E = kq/r2 dq = σdA dA = pi/2 * r' *dr' r = √(r'2+z2) 3. Attempt The lack of symmetry is what loses me in this question. I know I need to set up tiny quarter rings and then integrate from A to B but I don't know what to do about the vector notation.