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!

Re-writing a PDE

  1. Nov 13, 2014 #1

    joshmccraney

    User Avatar
    Gold Member

    1. The problem statement, all variables and given/known data
    Provide the missing steps to re-write the equation into one with just two terms $$u_{tt} - c^2(u_{rr}+\frac{2}{r}u_r) = 0$$

    2. Relevant equations
    Nothing, other than this looks similar to the wave equation hybrid. (I'm just speculating)
    Also, I'm a little uncertain what is being asked.

    3. The attempt at a solution
    Well nothing comes to mind. I am looking at this term: ##u_{rr}+{2}u_r/{r}##. So far nothing huge is coming to mind. I initially tried something like ##(u_r/r)'## and then ##(u_r \ln r)'## since they looked close to the above but nothing helps. Any creative ideas out there?

    Thanks a ton
     
  2. jcsd
  3. Nov 13, 2014 #2

    ZetaOfThree

    User Avatar
    Gold Member

    Try multiplying both sides by ##r^2##.
     
  4. Nov 13, 2014 #3

    joshmccraney

    User Avatar
    Gold Member

    Brilliant! Thanks a ton!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Re-writing a PDE
  1. PDE homework. (Replies: 1)

  2. Solving PDE (Replies: 1)

  3. Integration for a PDE (Replies: 2)

  4. PDE question. (Replies: 2)

Loading...