1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Help with asymptotic expansions, please

  1. Sep 26, 2010 #1
    Help with asymptotic expansions, please!!

    1. The problem statement, all variables and given/known data

    What is the behavior of asymptotic expansion of cosine integral function? Under what conditions should it be valid approximation to Ci(x)


    Ci(x)=- ∫∞x (cost/t)dt {in words} (Integral from x to infinity)(cost/t)dt


    2. Relevant equations

    -Intefral x to infinty(e^it/t)dt

    3. The attempt at a solution
    I have integrated the functions by part, i got the right answer with the right asymptotic expansion i.e. Ci(x) = (sinx/x)-(cosx/x)-(1.2sinx/x)+(1.2.3cosx/x^4)+R
     
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted