Thursday, January 30, 2014

4.4-4.5,5.1, due January 31

      The proofs involving Cartesian products of sets seemed a little more difficult.  It seems as if keeping all the different elements straight will be quite difficult.  However, the idea is fairly straight forward.  One need take the variables separately and remember what sets the individuals are elements of.  Of course, with practice, it will continue to become more clear.
      I find the counterexamples to be very useful.  I was in a debate earlier today, the opposing side used a generalization in a certain domain.  I thought of a counterexample that disproved their statement.  Though the counterexample did not prove their whole argument as false (because debates are much more subjective than mathematics) I felt logically validated for my use of a counterexample.

Tuesday, January 28, 2014

4.3-4.4, due January 29

      I found it difficult to understand the proof that verified a particular equality or inequality.  In the example, Result 4.16, I did not understand why (2x - 3y) squared is greater than or equal to zero was used.  I then realized that it came from working the result backwards until the equality could be shown in a way that was known to be true.  Because (2x - 3y) squared is always greater than or equal to zero, it is a great starting point for a direct proof.  It is now much more clear how to verify an equality or inequality.
      I found it interesting to begin working with proofs within sets because it allows us to solve much more general proofs involving sets of numbers rather than just individual number.  I like that we are expanding the tools that we are using to prove statements and expanding the situations in which those tools can be used.
  • How long have you spent on the homework assignments? Did lecture and the reading prepare you for them?
    • I have typically spent half an hour to three quarters of an hour on reading and another hour on homework problems.  When I wrote my second assignment in LaTeX, I spent about three hours completing it.  I do not anticipate them taking so long as I improve my skills in LaTeX and as I modify the template so that I do not have to redo so much in the assignments every time.
  • What has contributed most to your learning in this class thus far?
    • I have found that writing about the most difficult part of the reading has helped me to synthesize the material better.
  • What do you think would help you learn more effectively or make the class better for you? (This can be feedback for me, or goals for yourself.)
    • I think I would learn more if I could see where this will be applied in the various topics within math.  I sure as we continue through the year it will become clearer.

Saturday, January 25, 2014

4.1-4.2, due January 27, 2014

      The most difficult part of the reading was understanding the proofs involving congruence of integers.  Once I understood what the "congruent to... modulo" statement meant mathematically, I realized how simple the proofs were but until that point, it did not make much sense.
      I was rather excited when seeing the statements about how for a given integer x, 2 divides (x - 0) or 2 divides (x -1).  Also 3 divides (x - 0), 3 divides (x - 1) or 3 divides (x - 2).  It seemed exciting because for the general case of an integer n, n divides (x - 0), n divides (x - 1) ... n divides (x - (n - 1)).  This could be applied when dealing with proofs involving sets.  I am excited to deal with proofs of more general cases.

Thursday, January 23, 2014

3.3-3.5, due January 24

      The most difficult part was understanding proof by contrapositive.  I understand that "if P, then Q" is logically equivalent to "if not Q, then not P."  The confusion come when I try to keep straight which statement I am trying to prove true with a given result.  I am sure that I will understand it better with practice.
      I am impressed by section 3.5 on proof evaluation.  It was not until then that I realized that one proof could prove a variety of results so long as the results are logically equivalent.  Keeping this idea in mind could be particularly useful when employing different techniques to prove results.  It is also useful to be able to think critically about a given proof to determine whether it is a convincing proof or not.

Tuesday, January 21, 2014

3.1-3.2, due January 22

      The reading on proofs was interesting.  The most difficult part was when I skipped a page explaining the proof method to prove an integer is positive or negative.  Going back, realizing I missed a page, I read the idea.  It took me a few readings to realize what they were trying to say.  For an even number, the method is to show the formula can be written to as an arbitrary integer, multiplied by 2.  For an odd integer, it is to show an integer being multiplied by 2 then adding 1.  Understanding that made the following proofs make much more sense.
      I find the method shown to prove that an integer is positive or negative is very interesting.  I'm not sure how many significant proofs there are that would require this but it is good to understand the logic behind it.  This idea has expanded my knowledge on the functionality of substitution because in the end the part that is an integer could be expressed as a single variable.

Thursday, January 16, 2014

Chapter 0, due January 17

      The most difficult part of the reading was determining whether to use "that" or "which" in specific cases.  That is used to introduce a restrictive clause.  This is to specify the exact object being referred to.  Which is used for nonrestrictive clauses.  It seems to be used for giving more information about something.  It is for unnecessary or additional information.
      I thought it was very useful to have the conventions used in mathematical writing expressed clearly.  I had never thought before that it might be confusing to start a sentence with a symbol.  Now that I've read about good mathematical writing, I can be more conscientious about that which I write in this class and in future classes.

Tuesday, January 14, 2014

2.9-2.10, due on January 15

      This reading was fairly straight forward.  I did not understand why the negation of a quantified statement was being discussed and why during the negation, the inverted "A" was changed to the leftward-pointing "E."  I took a step back and really tried to understand the notation and it became clear that "if all elements x of set S for P(x)" is an statement then the negation would be there exists an element x that is an element of ~P(x) must be the negation.  It is now clear in my mind.
      I was interested by the notation for quantified statements as I often look up information on wikipedia and now I understand what more of the notation means.  This should help me when needing quick information related to math.

Saturday, January 11, 2014

2.5-2.8, due January 13

      A difficult element of the reading assignment was determining when a statement is logically equivalent without creating a truth table but I can see that would be time consuming when dealing with large compound statements.  Of course, the construction of a truth table is relatively easy but because I have limited experience with truth tables, I can see how simple it would be to make a mistake or error.
      From taking linear algebra and multivariable calculus, so often I heard the phrase, "if and only if" and understood it as it is not very ambiguous in English.  It is interesting to understand the biconditional in the more mathematical terms.  Understanding this with a formal definition will solidify my understanding of new mathematical ideas better.

Thursday, January 9, 2014

2.1-2.4, due on January 10

      The most difficult part of this sections reading was understanding the implication statement.  This is a statement formed from two given statements.  In this one, the statement is expressed "If P, then Q."  It was not clear what this statement meant at all.  I had to talk myself through developing a truth table in English as follows:

"If true, then true" is true.
"If true, then false" is false.
"If false, then true" is true.
"If false, then false" is true.

Looking at this truth table now, I know that I am repeating informations given by the implication statements themselves but it helped me to understand the idea.  After understanding this idea better, I continued on in the reading which confirmed that the understanding I had developed by myself was correct.
      Having had some experience with computer programming I can see the importance of understanding principles of logic.  When I saw the truth tables for one, two and three statements written out in Figure 2.1, it was exciting to think of all the potential outcomes of truth tables for large numbers of statements.  I understand a little better now how computers can become very powerful logic machines by having a large number of switches combined in different combinations.

Monday, January 6, 2014

1.1-1.6, due on January 8

      The most difficult part of the reading was understanding the explanation of indexed collections of sets.  Once an example was presented I had a clearer understanding of the purpose for the set I.  Each element of the set I act as a way to index subsets of the set S.  In fact the union of all sets S_alpha produces the set S.
      The most exciting part of the reading was section 1.6 about the Cartesian product.  I was excited to see that with this product, order matters.  Though I do not yet have a broad understanding of the implications that R x R is the set of all points in the Euclidean plane, I can see that this will be useful when working with functions.  I am excited to learn what there is to study when taking the product of R with itself in n dimensions.  I was also intrigued by pattern that the cardinality of the Cartesian product of 2 sets is equal to the product of the cardinality of the individual sets.

Introduction, due on January 8

What is your year in school and major?
       I am a Sophomore majoring in Chemical Engineering
Which calculus-or-above math courses have you taken?
      I have taken Math 302 and 303 at BYU.
Why are you taking this class?
      I missed taking a math class last semester and thought it would be fun and worthwhile to earn a minor in math.
Tell me about the math professor or teacher you have had who was the most and/or least effective. 
      My least effective math teacher did not engage me as a student or project his interest in math to me.  My most effective math professor showed his competence in the subject as well as relayed to the students how the subject matter related to his work and how it could be applied to other disciplines.
What did s/he do that worked so well/poorly?
      The less effective teacher did not show his passion for the ideas being taught.  He taught the material so that we could complete assignments but never help us to see the big picture.  The more effective one would take time aside from merely explaining the textbook but shared how he felt about the material.  It was interesting as he wold even share the philosophical significance of the models we were discussing.
Write something interesting or unique about yourself.
      I spoke with a British accent until I was 11 years old.
If you are unable to come to my scheduled office hours, what times would work for you?
      I can make it to scheduled office hour times.