Chaos, Fractals, and Dynamical Systems
Assignment #1
Due Thursday, September 9th
1. Read Chapters 1-4 in the book
2. Define the ``shift'' function S(x) on the interval
[0,1) by
S(x) = 10x (mod 1)
that is, S(x) is the fractional part of 10x. For
example, S(0.3245) = 3.245 (mod 1) = 0.245.
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Discuss the behavior of the orbit of 1/7 under S (use fractions,
not decimal approximations).
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Express each fraction in the orbit of 1/7 as a (repeating) decimal.
What is the pattern?
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Why do you think S(x) is called the shift function?
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Show that any point of the form k / 9, where k is an integer
from 0 to 8, is a fixed point of S. What do the decimal expansions
of these points look like?
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Give an example of a point in [0,1) that lies on a 2-cycle for S.
(Hint: the easiest way to do this is to use decimal expansions).
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Give an example of a point in [0,1) that lies on a 3-cycle for S.
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If a point is eventually fixed , what must its decimal expansion
look like?
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Explain why the orbit of every rational number is periodic or eventually
periodic.
3. Do the following problems in your book on pp. 26-27:
3, 5, 7deh, 11ad.