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am i allowed to do this......(C3 related) watch

    • Thread Starter

    I have a question which asked to me find the co-ordinates to the turning points of the equation: y= x/9+x^2

    I diffrentiated it using the quotient rule, and ended up with:

    9-x^2 / (9+x^2)^2 = 0

    could I re-arrange it so that the bottom half of the division goes to the other side with the '0'. Therefore it would be '(9+x^2)^2 ' multiplied by zero? So after, would I end up with '9-x^2 = 0' ?

    Certainly; in fact that's the only thing you can do. If you have a non-zero numerator, then no denominator could make the overall fraction equal to zero (except at infinity...)

    yeah, that's what you're meant to do
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Updated: January 16, 2010

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