A square wire loop of side length 2b carries a current circulating in the counterclockwise direction. The loop lies in the xy plane, centered at the origin, and with the sides either parallel or perpendicular to the x-axis, as shown below:
(c) Calculate the magnetic field B at the point A = (0, 0, z). You may use the following integration formula without proof:
integral from -b to b of dy / (b^2 + y^2 + z^2)^(3/2) = 2b / ((b^2 + z^2) * sqrt(2a^2 + z^2))