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Math Help - Find the first and second derivatives of the following function.

  1. #1
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    Find the first and second derivatives of the following function.

    f (x) = 9x^4-8x^3+9x

    f ' (x) =

    f '' (x) =
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    \<br />
\begin{array}{l}<br />
 f(x) = 9x^4  - 8x^3  + 9x \\ <br />
 f'(x) = 36x^3  - 24x^2  + 9 \\ <br />
 f''(x) = 108x^2  - 48x \\ <br />
 \end{array}<br />
\
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  3. #3
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    would you show me how u arrived at these answers please
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  4. #4
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    Quote Originally Posted by plstevens View Post
    would you show me how u arrived at these answers please
    Memorise and apply the basic rule!!

    If y = ax^n\, then \frac{dy}{dx} = n a x^{n-1}.
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  5. #5
    is up to his old tricks again! Jhevon's Avatar
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    plstevens, have you gotten up to the power rule as yet? i saw someone in another post do the derivative for you using the limit definition of the derivative and you followed it ok. how far along are you with derivatives?
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    Quote Originally Posted by Jhevon View Post
    plstevens, have you gotten up to the power rule as yet? i saw someone in another post do the derivative for you using the limit definition of the derivative and you followed it ok. how far along are you with derivatives?
    Since this is one of the many questions asked, I'd be very surprised if the power rule has not been taught ......
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  7. #7
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    i'm doing ok i'm still tryna get the hang of it
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