November 13th, 2010, 05:45 AM  #1 
Joined: Jun 2010 Posts: 80 Thanks: 0  Integration and expansion
I have 2 problems, a) a function f(x,t) should be expanded in or is it sufficient as ? a) if I can write functions is it possible to write f1(t)f2(t) as integral of the previous function, like : , or double integral ? 
November 13th, 2010, 07:08 AM  #2 
Senior Member Joined: Oct 2010 From: Changchun, China Posts: 492 Thanks: 11  Re: Integration and expansion
a)I don't know what you want to do, orthogonal decomposition or something else? b)Obviously not. 
November 19th, 2010, 02:55 AM  #3 
Joined: Jun 2010 Posts: 80 Thanks: 0  Re: Integration and expansion
I made a lot of mistake inside, for (a) i meant how to write generally the basis of all the function u(x,t) ? 
November 19th, 2010, 12:41 PM  #4 
Joined: Nov 2010 Posts: 13 Thanks: 0  Re: Integration and expansion
Sorry, but I have a question. I can't post my problem; since I need to type some mathematical formula and I don't know how to such stuff . I want to insert integration symbol, subscript, superscript, ...etc. Thanks in advance.. 
November 19th, 2010, 03:02 PM  #5 
Global Moderator Joined: Jul 2010 From: St. Augustine, FL., U.S.A.'s oldest city Posts: 11,555 Thanks: 101 Math Focus: The calculus  Re: Integration and expansion
This forum allows the use of LaTex to format equations and symbols, etc. Check out this topic which has some useful links. 
November 20th, 2010, 03:15 PM  #6 
Joined: Jun 2010 Posts: 80 Thanks: 0  Re: Integration and expansion
Well we could see as a complete Fourier transformation in k,omega, but I don't know why, physically, a "timebasis" seems a bit "naive", in the sense the future always remains hidden ? 
November 21st, 2010, 03:53 PM  #7 
Senior Member Joined: Oct 2010 From: Changchun, China Posts: 492 Thanks: 11  Re: Integration and expansion
There will allways be some cost (loss of energy or power etc.) doing a), even the function can be decomposed by the Fourier transform.


Tags 
expansion, integration 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
expansion  MATHEMATICIAN  Number Theory  5  September 4th, 2013 06:53 AM 
expansion  apoorva  Algebra  4  April 26th, 2013 10:20 PM 
Binomial expansion  hoyy1kolko  Probability and Statistics  6  December 7th, 2010 05:45 PM 
how to do this expansion  davedave  Algebra  1  November 19th, 2009 10:11 PM 
Expansion  Sarge99  Algebra  4  October 15th, 2009 05:51 PM 