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) = 10(mod 1)

that is, S(x) is the fractional part of 10x.  For example, S(0.3245) = 3.245 (mod 1) = 0.245.

  1. Discuss the behavior of the orbit of 1/7 under S (use fractions, not decimal approximations).
  2. Express each fraction in the orbit of 1/7 as a (repeating) decimal.  What is the pattern?
  3. Why do you think S(x) is called the shift function?
  4. 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?
  5. 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).
  6. Give an example of a point in [0,1) that lies on a 3-cycle for S.
  7. If a point is eventually fixed , what must its decimal expansion look like?
  8. 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.