10 points a rectangular box has dimensions l × l × d. the two square sides are held at electric potentials +vo and -vo respectively, whereas the four other sides are kept at ground. use the center of the box as the origin of your reference frame, with the z axis perpendicular to the square base. a) (1pt.) describe the boundary conditions. b) (3 pts.) set up the laplace equation for the space inside the box, using separation of variables. c) (3 pts.) give a series solution for the equation. justify your choice of functions based on the boundary conditions. d) (2 pts.) set up the equation to evaluate the coefficients (you will get full credit if the equation is correct, no need to solve it). e) (1 pt.) in the limit l > > d, prove that the field inside approaches the field of a capacitor.