Consider two thin disks, of negligible thickness, of radius R oriented perpendicular to the x axis such that thex axis runs through the center of each disk.The disk centered at x = 0 has positive charge density η, and the disk centered at x = α has negative charge density -η, where the charge density is charge per unit area.

What is the magnitude E of the electric field at the point on the x axis with x coordinate α⁄2 ? Express your answer in terms of η, R, α, and the permittivity of free space ∈₀.