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Math Help - help with easy derivative question half done

  1. #1
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    help with easy derivative question half done



    how do i do the last bit?

    im unsure with the "2" root x

    do i put 1 over 2 root x out in front of 2 and minus 1 from 2 root x at the end.

    i dont know how to write this or if its correct
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  2. #2
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    First, note \displaystyle -3 \cdot -8 =+24
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    oh yeah sorry missed the 2 negatives
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    What's the derivative of \displaystyle 2x^{\frac{1}{2}}?
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    2.5 over root x?
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    Half of 2 is not 2 and a half...
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  8. #8
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    The two alternatives you gave appear to be equivalent.
    \displaystyle \frac{1}{x^{\frac{1}{2}}} = \frac{1}{\sqrt{x}}

    Both are correct.
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    is this the correct answer

    thanks for all help
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  10. #10
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    its right
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  11. #11
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    Except that you wrote two different things for y'. The first, y'= 24x^{-9}+ 2x^{1/2}, is wrong because you haven't yet differentiated the second term.
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