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Math Help - Easy question on differentiation

  1. #1
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    Easy question on differentiation

    Hi I have a really easy question that I do not understand here.

    y = (2sqrt(x))/(1-x)),
    and for dy/dx I got (x+1)/(sqrt(x)(1-x)^2)

    Here's what I'm confused about,
    For what values of x is dy/dx zero.

    My answer will be -1 since if the numerator is zero, dy/dx will be zero but the answer says never..

    Thank you for your help!!
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  2. #2
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    Re: Easy question on differentiation

    Notice that the domain of your derivative is \displaystyle \begin{align*} x \in \mathbf{Z} ^{+} \backslash \{ 1 \} \end{align*}
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  3. #3
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    Re: Easy question on differentiation

    How did you know that the domain of this derivative is as such?

    Thank you!
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  4. #4
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    Re: Easy question on differentiation

    Square roots are only defined for nonnegative values, and denominators can't ever be 0.
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