# Linear & Abstract Algebra

- Vector spaces and linear transformations. Groups and other algebraic structures along with Number Theory.
 Meta Thread / Thread Starter Last Post Replies Views Views: 635 Announcement: Follow us on social media and spread the word about PF! Jan16-12 Please post any and all homework or other textbook-style problems in one of the Homework & Coursework Questions... Feb23-13 09:24 AM micromass 1 35,776 I'm unable to understand this generalization of vectors from a quality having a magnitude and direction, to the more... Jan14-13 10:29 AM danzibr 4 1,402 In this video: http://www.youtube.com/watch?v=FZz-Q-KBlpE At the time 2:10, I don't understand why we have to... Jan14-13 07:15 AM Artusartos 4 1,089 Perhaps forum members can advance science by solving this optimization problem from The Protein Engineer ... Jan13-13 04:10 PM homeomorphic 2 861 I don't know if this is the correct section to post this, but does Galois theory has any applications in physics? Jan13-13 03:47 AM Jim Kata 2 2,006 Pretty much what the title says. Suppose we have a topological vector space $(X,\tau)$ and $U\subseteq X$ is... Jan12-13 09:32 AM danzibr 5 1,281 Hi all, I have been asked the question by a friend of mine who was working on a computer algorithm where he needed... Jan11-13 03:01 PM HallsofIvy 4 1,280 Hello all, I am new to this forum but am glad I found it, I have a quick question about condition numbers and order... Jan10-13 06:08 PM AlephZero 5 1,227 Hello, I was wondering if this problem is one that is solvable, and if so, if I would be able to solve it in a... Jan9-13 11:31 PM hello95 3 1,104 Hey guys, lurked here a bit, but now I'm in this new math course right. So anyway it seems like a completely new... Jan9-13 06:59 PM sniper_spike 4 849 Hi guys, first post! I'm doing some side work on coupled oscillating systems, and I've almost found a procedure to... Jan9-13 03:39 PM Jack Jenkins 0 917 Hi, Let the linear system Ax=b. I am looking for literature describing how changes on coefficients matrix A affect... Jan8-13 05:01 PM yiorgos 0 619 I'm trying to understand the derivation of polynomial regression. Given data points: . So a 2nd degree curve will... Jan8-13 02:58 PM SteamKing 10 1,241 I have a question about the proof that I attached... 1) Since R/I is not the zero ring, we know that 1 \not= 0.... Jan7-13 09:01 PM Number Nine 1 834 I recently got (re)interested in C* algebras. Poking around, I gathered that there is some way of constructing a C*... Jan7-13 12:17 PM marcus 0 568 Hi I am going through Sheldon Axler - Linear Algebra Done right. The book States the Complex Spectral Theorem as :... Jan7-13 11:38 AM vish_maths 4 1,138 No not the trival solution but generally GCD(x,y) = 1 when GCD(A,B)=1 x =... Jan7-13 12:40 AM ramsey2879 0 1,009 Hello everyone! I'm a 1st grade student in a slovenian high school. Recently, I've became very intrested in numbers... Jan6-13 09:22 PM skiller 11 2,337 I have some technical questions about spans and bases which my textbook really does not cover very well. I would... Jan6-13 06:16 PM AlephZero 2 917 I have no idea what this is! Please can someone explain comparing to a 3x3 matrix? Jan6-13 05:19 PM mfb 3 1,102 Hello all, I have a question: assume in matrix M(n*n), each element M(i,j) of matrix is computed as M(i&)*M(&j) /... Jan6-13 01:06 PM sanaz 4 997 I am a bit confused about the page that I attached... I don't understand part (ii)... How can you compute XX? So... Jan6-13 12:07 AM Artusartos 6 831 Why do we have x-axis perpendicular to y-axis? Why not 45° or something else? Even if we keep any other angle other... Jan5-13 12:16 PM Studiot 9 1,624 I'm trying to compute the complexity of the quadratic program: \displaystyle\min_{\mathbf{X}} (\mathbf{X^TQX +C^TX})... Jan3-13 08:41 PM lavinia 3 762 Consider an m x n table containing single digits 0 to 9. So each cell contain the digits 0 to 9. My goal is to make... Jan3-13 11:01 AM mfb 7 2,234 Hi. Define a linear mapping F: M2-->M2 by F(X)=AX-XA for a matrix A, and find a basis for the nullspace and the... Jan2-13 11:59 PM nickthegreek 2 916 Hello, I have a simple(or not?) math problem: I have equations of 3 lines in R3 trought the origin: line l1: ... Jan1-13 08:12 PM chiro 5 1,384 Theorem : if S ={ v1 , .... , vn} spans the V.Space V , L={w1 , .... , wm} is set of linear independent vectors... Jan1-13 07:55 PM mathwonk 10 1,549 The logic that odd composite with least difference will be factored easily and large difference would factored hardly... Jan1-13 09:30 AM mfb 4 1,634 Hello everyone, I found that you're actively discussing math problems here and thought to share my problem with... Jan1-13 03:33 AM phd_student 0 1,006 Suppose that a = aBc where a and c are vectors and B is some matrix that changes as time "continuously" goes on -... Dec31-12 04:20 AM dotiozeros 0 805 Hey all, I have been playing around with a special type of matrix and am wondering if anyone knows of some literature... Dec30-12 11:21 PM orthogonal 4 1,455 Hi All, I have a hard time answering the following. I need some help. Let Z={a,b,c,d,e,f} and let X denote the... Dec30-12 01:31 PM laptopmarch 1 742 Is there any algorithm to form a magic square of any size with a desired magic sum ? Also can we make a magic square... Dec30-12 08:09 AM RamaWolf 6 2,108 The book I am going through says this : The below proposition is false for real inner product spaces. As an... Dec28-12 06:46 PM chiro 3 994 I was looking for a hint on a problem in my professor's notes (class is over and I was just auditing). I want to... Dec28-12 06:42 AM sammycaps 12 1,295 Question is : If m,k,n are natural numbers and n>1, prove that we cannot have m(m+1)=kn. My attempt : Using... Dec27-12 12:16 PM mathwonk 16 2,982 This may be a very silly question, but still apologies, I read in Sheldon Axler, that the inner product of two... Dec27-12 07:31 AM vish_maths 3 855 Hello, I was wondering, why is the vector projection useful in the way that it is presented? Why isnt just the... Dec27-12 03:30 AM Stephen Tashi 12 2,204 I've got a general question about Lie algebras, which is basically this: Q: What is there to be said about the Lie... Dec27-12 01:10 AM Couchyam 0 758 Video illustration Hello, Me and a friend, David Barrack, are non-mathematicians but we've been having fun... Dec25-12 11:34 AM micromass 2 2,039