IB Prized Writing Sevenoaks School IB Prized Writing 2014 | Page 112

Nina del Ser - Mathematics octopus | 7 (2) shows that the curve will preserve its elliptic character, irrespective of the value given to b, as long as b 1. When b0, it is clear that (2) generates a unit circle (which is therefore simply a special case of the ellipse, in which the two foci lie on top of each other), centered at the origin. Figure 4 shows what happens when the lengths of the primary and secondary rotors are identical (i.e. b1): Since the y-component of the position vector of the seat is always equal to zero, the seat will only move along the x-axis. figure 4 Thus, if the lengths of the primary and secondary rotors were equivalent, people would just travel back and forth in a straight line, which might be of some relief to nervous passengers! 111