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Homework Help: Uniiqueness of dx equation

  1. Jun 27, 2009 #1
    1. The problem statement, all variables and given/known data
    y' = y(siny) + x does this have a unique solution ,
    with the intial value of f(0)= -1
    3. The attempt at a solution

    the partial dervative with respect to y is
    del(x)/del(y) = siny + cosy(y) this is continous on the rectangle including
    (0 , -1 ) so this is unique.

    is this right
  2. jcsd
  3. Jun 28, 2009 #2


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    Science Advisor

    Yes, that is correct. Strictly speaking, for uniqueness you only requrire that f(x,y), in dy/dx= f(x,y), be "Lischitz" in y but that is implied by continuous derivative so that is sufficient.
  4. Jun 28, 2009 #3
    im just curious do you have your ph.d. in math
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