The figure below shows a system consisting of three charges, q1 = +6.00 MC, q2 = -4.00 MC, and q3 = -3.00 /C, at the vertices of a rectangle of length a = 5.85 cm and height b = 2.35 cm. Find the magnitude and direction of the electric field at a point halfway between the charges q1 and q2. 9 3 i20