In a two-dimensional motion of a particle, the particle moves from point A, with position vector r 1, to point B, with position vector r 2 . If the magnitudes of these vectors are, respectively, r 1 = 3 and r 2 = 4 and the angles they make with the x-axis are q 1 = 75º and q 2 = 15º, respectively, then find the magnitude of the displacement vector.