Recent content by hydralisks

Matlab: Urgent! My comp crashed and now I can't open my file anymore... it gives me this error message: http://i31.photobucket.com/albums/c374/haoming/matlab2938293.jpg Please help!

My attempt at understanding the question is actually meshed into my question above. I am aware of the 3 part guideline enforced on this forum but it is a little difficult to split my question and attempted understanding of it into two different blocks of words Thanks!

Homework Statement General questions about how cancer affects the cell cycle... 1) Does cancer actually speed up the individual phases of mitosis (prophase, metaphase, anaphase, telophase) ... ie metaphase occurs 100x sooner following prophase in a cancer cell compared to a normal cell...

To find out if 4 in an eigenvalue of A, decide if A-4I is invertible... So, if A-4I is invertible, then its cols are lin ind by IMT, and also there is only the trivial solution to A-4I=0, so thus 4 is not an eigenvalue of A ?

Because according to my book, If A's an invertible nxn matrix, then the eq. Ax=b is consistent for EACH b... this consistency would imply lin. independency?

Thanks!

If a question asks "does v1, v2, v3 span R4" can i just say no, regardless of what v1 v2 v3 is because v1 v2 and v3 is just 3 dimensions while R4 needs 4 dimensions?

Homework Statement Find a formal solution to the given initial boundary value problem. du/dt=5(d^2u/dx^2) 0<x<1 t>0 u(0,t)=u(1,t)=0 t>0 u(x,0)=(1-x)(x^2) 0<x<1 Homework Equations 1) u(x,t) = a0/2 + sum[an*e^(-b(n pi/L)^2*t) * cos(n pi x/L) 2) Fourier series equation...

Thanks for all the help! I definitely get almost all of the content now but I still don't really understand how you know to equate n=2k-1, instead of n= something else I know why 2k-1 works in this place but how do I think to use that when I'm doing the problem from scratch (without peeking at...

It's starting to make a little more sense, thanks. First off, is it just known that cos(npi) = (-1)^n? Does sin(npi) equal anything useful then? I also see (-1)^(n+1) in some of the solutions, is there a "formula" for that as well? So what if every even Bn did not = 0. How would I "combine"...

Sorry I'm kinda slow but you totally lost me. Unfortunately my book doesn't really explain this part. So is my answer "correct" but the book's answer is just a different way to write it? If not, is my Fourier series no longer a sum from 1 to infinity? If not, what is it and why did it change...

AH! Too much frustration has made me delusional! However, with the new answer: bn = (2/(n pi)) * (cos(n pi) - 1) I still don't get the correct answer as the book My final answer would be f(x) = sum of bn * sin(n pi x) according to the formula however, the books answer is: f(x) = (-4/pi) *...

In that case, I do not know how to do the integral. I'm not sure what's wrong, here's a step by step: bn = 2 * integral (-1 * sin(n pi x) dx) limits 0 to 1 = -2 * [-cos(n pi x) / (n pi)] from 0 to 1 = 2 * (cos(n pi)/(n pi) = 2 * (-1)^n / (n pi)

Homework Statement Compute the Fourier sine series for the given function: f(x) = -1 0<x<1 Homework Equations http://mathworld.wolfram.com/FourierSineSeries.html The Attempt at a Solution I got: bn = 2 * integral( (-1) * sin(npix) dx) from 0 to 1 = 2*(-1)^n/(npi)...

Ah, thanks so much. Sorry I actually have another question though, I am asked to compute the Fourier series for the following 2 part function: f(x)=1 -2<x<0 f(x)=x 0<x<2 I'm supposed to do this using the "Euler formulas" not the cos/sin formulas. However, I'm not sure how this two part...