Four point charges are at the corners of a square of side a as shown in the figure below. Determine the magnitude and direction of the resultant electric force on q, with ke, q, and a in symbolic form. (Let B = 3.0q and C = 4.0q. Assume that the +x-axis is to the right and the +y-axis is up along the page.) B a 9 a B magnitude direction counterclockwise from the +x-axis