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: Find 'k' for x(t)=k is solution for diff eq

  1. Sep 2, 2013 #1
    1. The problem statement, all variables and given/known data

    Find the value of k for which the constant function x(t)=k is a solution of the differential equation 6t^5dx/dt+7x−4=0.

    3. The attempt at a solution

    I have tried this several ways but no luck, here is one of my attempts,

    solve for dx/dt,

    dx/dt = (4-7x)/6t^5

    take the integral,

    x(t) = (1/6t^5)(4x-7x^2/2)

    and that doesn't help :P
    I am sure as usual I am missing something straightforward but I don't see it.
  2. jcsd
  3. Sep 2, 2013 #2


    User Avatar
    Homework Helper

    You have ##x(t) = k## therefore ##x'(t) = 0##.

    Plugging those in yields :

    ##(6t^5)(0) + 7k − 4= 0##

    I'm sure that you got this now. It's the same concept as in your prior thread.
  4. Sep 2, 2013 #3
    You know....
    At least missing these types of things typically only happens once.

    Thanks again!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted