Applied Discrete Structures
Friday, October 14, 2022
A new matrix multiplication record
Monday, September 26, 2022
Does learning about quantifiers help students understand limits?
A recent thread on the MAA member web site discussed how limits should be taught in Calculus I/II. One comment was that students who take a discrete math course, where quantifiers are discussed, might better understand the definition of a limit. What follows is a possible example that could be added to our section on quantifiers. Background: I taught a calculus workshop for mostly middle school teachers several years ago and I recall the most spirited discussion being around the idea that $0.999… = 1$.
Example: What does it mean that 0.999… = 1? The ellipsis (…) implies that there are an infinite number of 9’s on the left of the equals sign. After many years of struggling with what this means, mathematicians have come up with a universally accepted interpretation involving quantifiers. It is that
$$(\forall \epsilon)_{\mathbb{R}^+} ((\exists N)_{\mathbb{P}})(n\geq N \Rightarrow |1- 0.\underbrace{99..9}_{n\,9’s}| \lt \epsilon))$$Thursday, August 5, 2021
UMass Lowell Faculty Word Search
We have another month before the semester gets started, so here is a word search puzzle you can do while you relax in your back yard or the beach. Most of the names are the last names of UMass Lowell Math Faculty and Staff. A few individuals had names too long for the puzzle app to handle, so their first names are used instead. Also, a few of the names are spelled right to left or bottom to top.
Monday, June 14, 2021
Version 3.8 of Applied Discrete Structures is now available!
All forms of Applied Discrete Structures - Version 3.8 are available. As always, the web and pdf versions are free. The print copies increased in price due to increases in paper costs passed on by Lulu. The full version is now $41.00. I'm not so concerned since very few students buy it.
I didn't keep track of the changes in the new version, but here is a list some of the changes/additions that I recall:
- Exercises in Section 7.1 were rearranged and augmented
- A new exercise in Section 8.2 reviewing quantifiers in the context of sequences.
- A few operations tables were added in Section 11.4 - Modular Arithmetic, including one multiplicative group.
- An exercise similar to one of our final exam questions this spring was added to section 13.1 on posets and lattices.
- A new example was added to the section on algebraic coding (15.5) with a follow-up exercise.
Wednesday, April 28, 2021
UML OERscars - 2021
The UMass Lowell chapter of MASSPIRG is active in promoting the use of OER materials for students. I fully agree that it's worth a try for any course. I'm happy to have been recognized by them at this year's inaugural OERscars awards ceremony for Applied Discrete Structures. The good news for UML students is that there were faculty from every college recognized for developing and/or using OER materials for their courses. Congratulations to all OERscar winners!
Applied Discrete Structures has be