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Differential equation problem

  1. Mar 20, 2014 #1

    lap

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    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

    HallsofIvy

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    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

    HallsofIvy

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    lap has edited his question and changed it completely. My first response was to a different question.
     
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