$12.($a$)$ A point charge q is located a distance d from an infi$-$nite plane. Determine the electric flux through theplane due to the point charge. $($b$)$ What If$?$ A pointcharge q is located a very small distance from the centerof a very large square on the line perpendicular tothe square and going through its center. Determine theapproximate electric flux through the square due to thepoint charge. $($c$)$ Explain why the answers to parts$($a$)$ and $($b$)$ are identical.