IB Prized Writing Sevenoaks School IB Prized Writing 2014 | Page 126

Nina del Ser - Mathematics octopus | 21 The maxima due to Β and Γ are shown as red and purple respectively (please note that the red lines hide any purple lines underneath them). Also, it is not necessary to include the lines due to pn-qm because we know that this value will be a multiple of the highest common factor, for the following reason: Β and Γ can be re-written as multiples of their higher common factor, which we shall call k. Therefore, Βmk, Γnk, where n,mΕ Z  Β-Γ(m-n)k  the term pn-qm is simply a multiple of the highest common factor and does not need to be considered. Conclusion We have shown that it is possible to determine the rotational symmetry of any curve generated by a Dodeca- pus, provided we are given the speeds of its rotors and that these speeds are rational numbers. The method we have used to do this could also be extended further and applied to any Multipus (an Octopus with any number of extra arms). Below are some figures generated by Multipuses; you can see that finding the highest common factor of the numerators of the speeds yields the rotational symmetry of the curves: 8 figure 62: Hexadecapus with Ω3, Γ 6, ∆ 9 figure 63: Duodecapus Ω4, Γ  , ∆ 12, Ε 16 figure 64: Duotetradecapus Ω8, Γ 16, ∆ 24, Ε 40, Ζ 32 figure 65: Duooctadecapus Ω6, Γ 9, ∆ 18, Ε 15, Ζ  , Η12 9 3 5 125