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    I got the right answer for the above question by just letting P = 1/x and Q = rootx then using the other method..

    Why have they multiplied by the integration factor? I mean are there particular situations where you use the above method?
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    (Original post by GPODT)


    I got the right answer for the above question by just letting P = 1/x and Q = rootx then using the other method..

    Why have they multiplied by the integration factor? I mean are there particular situations where you use the above method?
    The standard method to solve

    \dfrac{dy}{dx} + P(x) y = Q(x)

    involves use of the integrating factor.

    Note that you may not use it if you can recognise the derivative of a product on the LHS (if not, the IF will turn it into the derivative of a product).
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    Thanks. I know you use the integrating factor (I did this) but I got the answer without multiplying by the integrating factor. I just wrote it in this form (after finding the integrating factor):




    My question is why did they multiply by the integrating factor? And in what situations do you use this?


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    (Original post by GPODT)
    Thanks. I know you use the integrating factor (I did this) but I got the answer without multiplying by the integrating factor. I just wrote it in this form (after finding the integrating factor):




    My question is why did they multiply by the integrating factor? And in what situations do you use this?


    Posted from TSR Mobile
    You've done the same thing but in a less explicit way.
 
 
 
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