Math 381W Homework Assignments - Spring 2011

All assignments will emphasize writing rigorous proofs. Make sure you justify every single step and statement you make. Provide proper references from the textbook (such as Proposition X or Definition Y).


Homework #1 - Due Tuesday, January 25, in class

Chapter 1, pages 44-45: problems 4, 6

Chapter 2, pages 91-92: problems 1, 2, 6, 8, 9

Assignment 1 solutions


Homework #2 - Due Tuesday, February 1, in class

Chapter 3, Exercises on betweeness (pages 146-148): problems 4, 5, 9, 11, 12

Assignment 2 solutions


Homework #3 - Due Tuesday, February 8, in class

Chapter 3, Exercises on congruence (pages 150-152): problems: 24, 26, 27, 29, 32

Assignment 3 solutions


Mini-project - Due Tuesday, February 22, in class

Write an essay about the taxicab plane described in Major Exercise 6 (Chapter 3, page 156). Here is a list of what you may want to include in your essay: (i) state and explain the new geometry, (ii) provide some historical background, (iii) address most (preferably all) points of the exercise 6, (iv) discuss practical, real-world applications of such a geometry. And of course, you are certainly encouraged to be creative and add to this list.

Important notes

  • Essay size and format : essays should be at least 4 and no more than 8 pages long. I strongly encourage you to use a word processor to type the text. Diagrams and drawings can be done by hand. Each page should have 200-250 words. Also pay attention to grammar and spelling, crucial aspects for successfully conveying ideas in essays (and proofs for that matter).

  • You are encouraged to consult books, articles, online material, etc, as long as you reference the sources properly. Also, if you seek inspiration from such sources, you are not allowed to simply copy that work into your essay. You should restate the ideas and the material that you choose to present using your own words, including your own views and perspectives on the respective topic/ issue.

    Academic dishonesty (including plagiarisms) is very well described on the university policies webpage:

  • http://www.sfu.ca/policies/files/Students/S10.01.pdf

  • Excellent tutorial for understanding plagiarism (on SFU library webpage): http://www.lib.sfu.ca/help/tutorials/plagiarism-tutorial

    General comments after marking the mini-projects: Overall we were quite impressed by the level of research and thought put into these papers. Very frequently, the results made enjoyable and instructional reading. For the most part, the mini-projects successfully conveyed an introductory summary and some original results of Taxicab Geometry. The average was 7.5 out of 10. We made extensive comments to provide as much feedback as possible. The main comment that applies to most of you relates to proper citation. See the "Important notes" for the final project listed on the course home page. There is an item that discusses citation. Read the information provided by the library link and learn how to reference properly.


    Homework #5 - Due Tuesday, March 8, in class

    Chapter 4, pg. 194-200: Exercises 9, 12, 14, 28, 32 and Major Exercise 1.

    Assignment 5 solutions


    Homework #6 - Due Tuesday, March 22, in class

    Chapter 5, pg. 228-230: Exercises 2, 3, 5

    Chapter 6, pg. 269-275: Exercises 1, 2(a-c), 12

    In Exercise 1 (Chapter 6) I want you to discuss individually each item in that list. I am not too keen on you adding to the list, I would rather want to make sure you understand the importance of the statements already listed. For instance, if appropriate, comment on whether the respective statement is equivalent to the Euclidean parallel postulate or to a weaker axiom/ property, such as the plane being semi-Euclidean. In other instances you could show that the statement is intrinsic to Euclidean geometry and it does not hold in hyperbolic geometry. Justify your answers. In some instances you can invoke results we proved in class, in others (such as item 1) you have to come up with your own proofs and interpretations. And, as the first line says, this is perhaps the most important exercise in the book, so make sure you treat it convincingly.

    Assignment 6 solutions


    Homework #7 - Due Tuesday, April 5, in class

    Chapter 6, pg. 269-275: Exercises 7, 8, 9

    Chapter 7, pg. 358: Exercises P-1, P-4.

    Assignment 7 solutions