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!

Differential equation problem

  1. Mar 20, 2014 #1


    User Avatar

    The question ask to determine whether y = φ(x) = sqrt ( x - 1 ) is a solution of the differential equation 2yy' = 1.
    Last edited: Mar 20, 2014
  2. jcsd
  3. Mar 20, 2014 #2


    User Avatar
    Science Advisor

    As far as "determine whether y = φ(x) = sqrt ( x - 1 ) is a solution of the differential equation 2yy' = 1" is concerned, there is no reason to "rewrite the equation". If y= sqrt(x- 1)= (x-1)^(1/2) then y'= (1/2)(x- 1)^(-1/2) so that 2yy'= 2(x- 1)^(1/2)[(1/2)(x- 1)^(-1/2)= what?

    As for the rest, I don't see how that has anything to do with the problem. Are you sure you haven't looked up the solution to the wrong question?
  4. Mar 20, 2014 #3
    Your wording is a bit confusing but if you're trying to determine if y(x) is a solution to your differential equation, all you have to do in plug y(x) into the equation and check if it holds.
  5. Mar 21, 2014 #4


    User Avatar
    Science Advisor

    lap has edited his question and changed it completely. My first response was to a different question.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted

Similar Threads - Differential equation problem Date
Differential Equation Problem Mar 14, 2018
Solution to complex valued ODE Feb 15, 2017
Differential Equation Initial Value Problem Feb 14, 2017
Snow Plow Problem Feb 5, 2017
Projectile Motion problem involving air resistance Jan 25, 2017