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: Existence, Uniqueness of a 1st Order Linear ODE

  1. Sep 10, 2011 #1
    1. The problem statement, all variables and given/known data

    Solve the Cauchy problem:

    (t2 + 1)y' + etsin(t) y = sin(t) t2
    y(0) = 0

    2. Relevant equations

    y'(t,y) + p(t)y = g(t,y)

    Integrating factor e(integral of p(t))

    3. The attempt at a solution

    I tried finding an integrating factor, but it came out ugly. I couldn't solve the integral.

    e(integral of) (et * sin(t)) / (t2 + 1)

    Then I tried separating, and it didn't work out too nice either. I was considering using those psi things (as in, an exact equation approach) to find an answer, but the homework topics do not involve those. Instead, the topics are Existence and Uniqueness, Autonomous Eqns, Modeling with 1st Order ODEs.

    So how do I even start this question??
  2. jcsd
  3. Sep 10, 2011 #2
    Upon reading my notes, perhaps we have not yet covered the strategy required to attack this problem? Any help is appreciated regardless.
  4. Sep 10, 2011 #3


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    I don't think you will find any standard method to solve that. Most DE's aren't exactly solvable by elementary functions and that looks like a good candidate.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook