Recent content by skoker

i have come across quite a huge list of free math books from the project Gutenberg, they scan in old books. but theses have been converted to latex so they are REALLY nice to read. they even have links in the pdf. there is a huge list so take a look...

Vim is the best! i use vim for my main editor to write c code. it is a great editor and for programming and latex. there are lots of plugins for c and latex. if you use vim on windows from the installer it does not have python support. but on Linux it does. and you can use python plugins. this...

ok thanks i will take a look at those. i am doing the 3d transformation matrices on vectors and the algebra is quite nasty. it is hard to figure out once there are a few matrices. i have no idea if the results are correct without a drawing or picture. cheers

does anyone know an easy to use 3d plotting software with vectors? i have been using maple for some things but 3d plotting vectors and transformations is really slow in maple. i really like geogebra but it can only do 2d vectors. any suggestions?

that is true. i can not think of any of the matrix properties that would be a restriction with \( abcd \quad n \times n \). A is consistent and invertible. so i would not have any problems i think.

find the LU-factorization of $A=\begin{bmatrix} a\ b\ \; \\ c\ d\ \; \end{bmatrix}$ that has 1's along the main diagonal of L.are there restrictions on the matrix A?\( A=\begin{bmatrix} \;a\ b\ \; \\ \;c\ d\ \; \end{bmatrix} \) \( U=-\frac{c}{a}r_1+r_2\rightarrow r_2\begin{bmatrix} \;a\ b\ \...

i suppose that is redundant or unnecessary. i was not sure if it needs a conclusion with the 'therefore'.

i have a simple proof is this correct? prove that if \(A^2=A\), then either A=I or A is singular. let A be a non singular matrix. then \(A^2=A, \quad A^{-1}A^2=A^{-1}A, \quad IA=I, \quad A=I\) therefore \(A^2=A.\)

Re: clearing fractions with row opperations. so i think i figured it out. sorry if this is so basic, i just started in the linear algebra book. i was doing the \( 3 \times 3, \; A^{-1} \) with Gauss elimination by hand and always getting it wrong.

i know you have the 3 row operations. add two rows. multiply a row by a constant. add a multiple of a row to another. my question is can you multiply a row by a constant to clear a fraction at any time so long as you end up in row echelon form. no matter what operations you do the result in...