Two point charges with the same magnitude but opposite signs are fixed to the ends of the base of an isosceles
triangle as shown (+q on the left and-q on the right). The electric field at the midpoint (point M) between the
charges has a magnitude of EM. The electric field directly above the midpoint between the charges at point P has a
magnitude of Ep. The ratio of these magnitudes EM/Ep = 9.0. Find the angle a in the drawing