I got lost in the proof of Theorem 8.30.
As I was reading this section, I kept thinking about how difficult it would be to come up with these theorems and then to go about proving them. Which comes first: the pattern to see the result of the theorem or the steps that are gone through in the theorem and then check if the idea actually works? Whatever the process is, it seems like it would be really tedious and difficult.
Saturday, December 5, 2009
Tuesday, December 1, 2009
Section 8.3 due 12/1
I don't have specific questions, but I would like some further insight into the Second and Third Sylow Theorems because I don't feel like I understand them.
I like the First Sylow Theorem but I didn't understand it until I read the example. The notation is confusing. They should do something about that.
I like the First Sylow Theorem but I didn't understand it until I read the example. The notation is confusing. They should do something about that.
Sunday, November 29, 2009
Section 8.2 due 11/29
I was hoping for an example to accompany more of the theorems because I don't understand them very well.
This section seemed much harder to understand than the previous sections. I just wish I could understand it better so that I could ask more questions.
This section seemed much harder to understand than the previous sections. I just wish I could understand it better so that I could ask more questions.
Tuesday, November 17, 2009
Review due 11/17
I need to review a lot before taking the exam: right and left cosets, order of groups, subgropus generated by S, cyclic groups, quotient groups, etc.
I would benefit from going over 16, 24,25, or 26 of 7.7 (p. 221).
I would benefit from going over 16, 24,25, or 26 of 7.7 (p. 221).
Thursday, November 12, 2009
Section 7.7 due Nov 12
I don't understand the second example on p 218. How is N+(0,0)=N+(1,2) in that example?
It is interesting that cyclic quotient groups G/Z(G) imply that G is abelian. I think that is a interesting correlation.
It is interesting that cyclic quotient groups G/Z(G) imply that G is abelian. I think that is a interesting correlation.
Tuesday, November 10, 2009
Extra Credit Colloquim
Dr. Helen Moore talked about her career as a mathematician in the pharmaceutical field. As a researcher, she and a team of other mathematicians try to figure out what the optimal therapy for HIV and Leukemia patients are.
It was a really interesting lecture because I don't generally care about the applications that are shown in math classes--applications that are more geared toward the engineers in the classes. But this showed how math could be applied to helping fight cancer, something that we always think about medical doctors being able to achieve.
It was also interesting because of the importance of precision in the mathematics. Dr. Moore talked about doctors administering drugs to patients--different levels and different combinations of drugs. She said it was important to be accurate in their models because you wouldn't be able to give a person massive amounts of drugs without there being negative effects. (The FDA and drug companies would monitor that more, but it was still important to take into consideration in their models.)
It was a really interesting lecture because I don't generally care about the applications that are shown in math classes--applications that are more geared toward the engineers in the classes. But this showed how math could be applied to helping fight cancer, something that we always think about medical doctors being able to achieve.
It was also interesting because of the importance of precision in the mathematics. Dr. Moore talked about doctors administering drugs to patients--different levels and different combinations of drugs. She said it was important to be accurate in their models because you wouldn't be able to give a person massive amounts of drugs without there being negative effects. (The FDA and drug companies would monitor that more, but it was still important to take into consideration in their models.)
Section 7.6 due Nov 10
Does left/right congruence affect other things? (For example, if there were a "divides" then things might get messy.) Can you further explain the definition of "normal" because they try to make a distinction at the top of p. 212 but I don't understand what they are getting at.
I was trying to decide if I like groups or rings better. I think I like groups better. You can define the group operation however you want as long as it follows the guidelines of a group.
I was trying to decide if I like groups or rings better. I think I like groups better. You can define the group operation however you want as long as it follows the guidelines of a group.
Thursday, November 5, 2009
Section 7.5 (part 1) due November 5
Can we go over Corollary 7.24 and review what right cosets are? And can you explain Lagrange's Theorem and the notation they use in the theorem?
The beginning of this is mostly review, so we have learned most of it before, applying it to rings and integers.
The beginning of this is mostly review, so we have learned most of it before, applying it to rings and integers.
Tuesday, November 3, 2009
Section 7.4 due November 3
I don't understand the inner automorphism of G or Theorem 7.20.
It seems natural that this section is in here since there was a section on isomorphisms for rings.
It seems natural that this section is in here since there was a section on isomorphisms for rings.
Saturday, October 31, 2009
Section 7.3 due Nov 1
I didn't understand the proof of Theorem 7.11. Many of the other theorems are obvious.
As in rings, it is helpful to know that G is a group so that you don't have to prove as many things, like associativity in subgroups.
As in rings, it is helpful to know that G is a group so that you don't have to prove as many things, like associativity in subgroups.
Thursday, October 29, 2009
Section 7.2 due 10/29
It says a^n=aaa...a (with n factors) but (ab)^n does not necessarily imply (a^n)(b^n). So does (ab)^n=(ab)(ab)(ab)(ab)...(ab) (with n factors of ab)? They said that we will use standard multiplicative notation, so shouldn't that mean that this is commutative?
The proof of part one of 7.5 was at first confusing but, upon further review, made a lot of sense and seemed extraordinarily creative. Then again, when are proofs not creative?
The proof of part one of 7.5 was at first confusing but, upon further review, made a lot of sense and seemed extraordinarily creative. Then again, when are proofs not creative?
Tuesday, October 27, 2009
Section 7.1 (part 2) due 10/27
The section says that a nonzero ring is never a group because of the zero ring. Since multiplication is such a straightforward operation, why do they not make an exception in the group to say that for everything else, the group will work?
I thought the reflections were interesting because I haven't thought about reflections of shapes for a long time. I also think the theorems were somewhat interesting because they find some groups for us.
I thought the reflections were interesting because I haven't thought about reflections of shapes for a long time. I also think the theorems were somewhat interesting because they find some groups for us.
Saturday, October 24, 2009
Section 7.1 (part 1) due Oct 25
With rings they say that if ab=ba then the ring is commutative. On p 163 they say that a group is abelian if it satisfies the commutativity axiom. Why is there a special word for it? Do they do it since multiplication commutativity is much more simple than what some operations can be? Can all groups' permuations be represented by an array?
Function composition is associative, but how often are composed functions commutative? Do they have to be simple, linear functions? That would be something interesting to explore a little bit. (Of course, they must not be too rare because there is a special name just for this type of group.)
Function composition is associative, but how often are composed functions commutative? Do they have to be simple, linear functions? That would be something interesting to explore a little bit. (Of course, they must not be too rare because there is a special name just for this type of group.)
Thursday, October 22, 2009
Midterm course evaluation
1. The homework and the blogs contribute most to my learning. I like the blogs because it forces me to read the section before we talk about it in class. I think it helps you teach better because then you know what to spend more time talking about. The homework helps because it really is challenging and gives us a good idea of what kinds of questions might be on the test.
2. In class, it seems like we go over the proofs really fast. I feel like I am so busy taking notes that I am not taking everything in. (This doesn't seem to be true for the majority of the class, though, since they ask lots of questions.)
2. In class, it seems like we go over the proofs really fast. I feel like I am so busy taking notes that I am not taking everything in. (This doesn't seem to be true for the majority of the class, though, since they ask lots of questions.)
Tuesday, October 20, 2009
Review for test due Oct 20
I think ideals and quotient rings (and basically all of chapter 6) will be the most important topics that we have studied that will be on this test.
Ironically, I feel most uneasy about quotient rings. It seems like there is a lot to know about them (even though it is really only covered in one section) or at least a lot that can be proven from them, thus, it is necessary to study this more intensely for the test.
The question I would like worked out in class comes from 6.3 #11: Show that the principal ideal (x-1) in Z[x] is prime but not maximal.
Ironically, I feel most uneasy about quotient rings. It seems like there is a lot to know about them (even though it is really only covered in one section) or at least a lot that can be proven from them, thus, it is necessary to study this more intensely for the test.
The question I would like worked out in class comes from 6.3 #11: Show that the principal ideal (x-1) in Z[x] is prime but not maximal.
Saturday, October 17, 2009
Section 6.3 due 10/18
I don't understand the concept of a maximal ideal. And why can there be multiple maximals?
It is neat that all the concepts we have learned are interrelated and all the theorems relate these concepts. (Unfortunately, I don't understand some of these individual concepts so I can't yet see the bigger picture for 6.3.)
It is neat that all the concepts we have learned are interrelated and all the theorems relate these concepts. (Unfortunately, I don't understand some of these individual concepts so I can't yet see the bigger picture for 6.3.)
Thursday, October 15, 2009
Section 6.2 (part 2) due 10/15
I don't fully understand the terms "natural homomorphism" or "homomorphic image." It says that if S is a homomorphic image of R then R and S might have the same algebraic properties.
It seems that this section is important because it relates things that can be helpful when writing proofs. It is interesting that the section says, "A concept developed with one idea in mind may have unexpected linkages with other important mathematical concepts. That is precisely the situation here." It's neat that there are other results than just what they had wanted.
It seems that this section is important because it relates things that can be helpful when writing proofs. It is interesting that the section says, "A concept developed with one idea in mind may have unexpected linkages with other important mathematical concepts. That is precisely the situation here." It's neat that there are other results than just what they had wanted.
Tuesday, October 13, 2009
Section 6.2 due 10/13
More than any other section in the book, I am having a hard time visualizing this (as much as Abstract Algebra can be visualized). In Theorem 6.8, are a, b, c, and d representing numbers? All of this new notation, including and especially "R/I", will take some getting used to.
If I understand this section accurately, then this is the method behind doing multiplication in my head. For example, if I={x in R 3y=x} and a=2, then 83=a+nx=2+(27)(3). Is this what they are saying?
If I understand this section accurately, then this is the method behind doing multiplication in my head. For example, if I={x in R 3y=x} and a=2, then 83=a+nx=2+(27)(3). Is this what they are saying?
Monday, October 5, 2009
Section 5.2 due 10/6
I don't understand it Theorem 5.7 when it talks about F* being an isomorphic subring of F[x]/(p(x)). How is F* different from F?
This is pretty straight forward because a lot of theorems about rings are now applied to polynomials, like the rules of modular arithmetic. However, there are some new theorems that, to me, don't seem as obvious as others, but will probably be helpful in proofs.
This is pretty straight forward because a lot of theorems about rings are now applied to polynomials, like the rules of modular arithmetic. However, there are some new theorems that, to me, don't seem as obvious as others, but will probably be helpful in proofs.
Thursday, October 1, 2009
Sections 4.5 and 4.6 due 10/1
Theorem 4.29 says that if a polynomial in the reals is irreducible then it is either of degree one or two. In the proof of it, it says that this is not necessarily the case--that higher degrees have roots in the complex numbers. Because of the way it is stated in the theorem, though, it makes me wonder if I am understanding it correctly. Are there really only irreducible polynomials of degrees 1 and 2?
There are many theorems in 4.5 about primes, coefficients, etc. Some of them seem obvious while others seem brilliant. All of them make me wonder if they are applicable. (I suppose they are because they are in the textbook.)
There are many theorems in 4.5 about primes, coefficients, etc. Some of them seem obvious while others seem brilliant. All of them make me wonder if they are applicable. (I suppose they are because they are in the textbook.)
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