Wednesday February 7th

Reminders and Comments:

  • You have a groupwork and proof quiz on Friday.
  • Quizzes are generally handed back next lecture day.  Please frequently check your grades on canvas for correctness and completeness.
  • Tips for coming to office hour:  bring your past work.  If you have a question about a quiz problem, have a suggested correct solution or re-written proof to look at.  Be prepared with specific questions.
  • Toward the end of semester I will give you some extra opportunities to demonstrate missed badges, but this opportunity is not unlimited — it will be an extra opportunity for 2-3 badges by doing extra work.  The only way to guarantee success is to consistently study and master badges each week throughout semester.
  • The undergraduate math club holds talks you may be interested in:  Undergrad Math Club.

To do for Wednesday’s class:

  • Please finish the worksheet on Setting up Contradiction that we started in class today.  We will take it up together.
  • Please write a new, good copy of a correct proof for the last proof quiz, as applicable (i.e. if you didn’t score perfectly).  If you scored (0, 1, or 2) out of 4 on the Reasoning Score of Quiz #2, be aware that this likely indicates that you need to work extra to keep up with the class.  Everyone can master the material in this class, but the class does go at a certain fixed pace, and you are in a “catch up” position at this point.  I’m happy to talk to you in office hour.  Please bring your good copy of the proof to office hour so we have something to work with.

Monday, February 5th

Announcements and reminders:

  • Today we will have another badges quiz with sets badges.  The badges are:
    • Sets I: basic definitions (set, element, equality, empty, cardinality)
    • Sets II:  operations (union, intersection, difference, universe, complement, Venn diagram)
    • Sets III:  Set-builder notation
    • Sets IV: ordered pairs, Cartesian products and powers, subset and powersets, including cardinality
    • Logic IV:  negating statements
    • Proofs I:  setting up a proof by contradiction
  • The new groupwork has been posted.  I will go one more week before remixing groups, but as always, contact me if you have trouble scheduling 2 hours or any other problem.  If you have 6 people in one group, consider breaking into two groups of 3.

For today’s class:

  • We will mostly focus on proofs by contradiction today.  (The Logic IV and Proofs I badges are relevant to the study of proof by contradiction, so they will begin to be available on the badges quizzes.)
  • Bring your homework about “threeven” that was assigned in the previous daily post.
  • Read Hammack, page 111 (the first page of Chapter 6), and from page 113 to the end of Section 6.2 on page 116.  In a couple spots, there’s a bit of notation from Boolean Logic in this chapter, because Hammack assumes we have covered Chapter 2 before getting to Chapter 6.  Consider it an exercise in adaptive reading — just work around the notations you don’t know.  We will be working on Boolean Logic soon, and for now skipping over his reference to it still leaves a very useful reading.
  • Study for the Badges Quiz.  My advice: look your scores up on canvas, look over your returned quiz, and decide on 2 or 3 badges you’d like to focus on getting full credit for this week.  (Study a few excellently, instead of all of them passably.) To study, it is helpful to find the relevant material in Hammack and do exercises (odd answers are in the back) to brush up on the concepts.  If you have questions about the badges quiz material, I can take them up at the beginning of class Monday before we do proof by contradiction.