Information --- Staff --- Homework --- Reading/Lecture note --- Newsgroup --- Feedback

Assignment 5: Sets and Functions

Due 04.Feb.24 (Tue) 17:00

Before you tackle the homework, remind yourself of our general hw policies.

Reading: Rosen 1.5 ("Methods of Proving Theorems"), 1.8, 7.1 (skim), and 7.3 (digraphs only).

  1. (2pts) Section 1.5, #26. (p. 75; 4ed p.184 #22) (Q closed under ċ)
  2. (2pts) Section 1.5, #28. (p. 75; 4ed p.184 #28) (Q*(R-Q) in? (R-Q))
  3. (2pts) Section 1.5, #64. (p. 76; 4ed p.185 #62) (Q closed under expt?)
  4. (2pts) Section 7.1, #2.
    Divides on {1,2,3,4,5,6}.
    For 2b, instead draw the graph (as in class and the second half of Section 7.3.)
  5. (2 3pts) Section 7.1, #4 and #10.
    Relation properties (taller?, bornSameDay?, etc).
    Group your answers together, for #4 and #10.
  6. (2pts) Section 7.1, #10. (Merged into previous problem.)
  7. (2pts) Section 1.8, #2. (Fourth edition -- Section 1.6: #2) [Don't confuse Section 1.8 with the other end-of-chapter questions!]
    Note: the square-root symbol denotes a (single-valued) function, the positive number which squares appropriately. (To think about: in the complex plane, how can you specify which of the possible answers is returned by sqrt? I.e. why is sqrt(-1) = i, not -i?)
  8. (2pts) Section 1.8, #8. (Fourth edition -- Section 1.6: #6)
  9. (2pts) Section 1.8, #14. (Fourth edition -- DNE)
  10. (2pts) Section 1.8, #16. (Fourth edition -- DNE)
  11. (2pts) Section 1.8, #18. (Fourth edition -- Section 1.6: #14)
    You can use the result from class, that "f 1-1 and onto" is equivalent to "f invertable".
  12. (2pts) Section 1.8, #30. (Fourth edition -- Section 1.6: #24)
  13. (3pts) Section 1.8, #48. (Fourth edition -- Section 1.6: #42)
    14. Information --- Staff --- Homework --- Reading/Lecture note --- Newsgroup --- Feedback
    Comp280 Home Please notify us of any broken links, etc. Last modified 2004.Feb.18.