Results 1 to 7 of 7

Math Help - 2nd Derivatives

  1. #1
    Newbie
    Joined
    Mar 2009
    Posts
    21

    2nd Derivatives

    Okay I know how to go about getting a derivative and 2nd derivatives. However, for this problem I can't figure out how to get to the right answer.

    this is the function f(x) = x(x-4)^3
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,614
    Thanks
    1581
    Awards
    1
    Quote Originally Posted by sgonzalez90 View Post
    Okay I know how to go about getting a derivative and 2nd derivatives. this is the function f(x) = x(x-4)^3
    The first derivative is f'(x)=(x-4)^3+3x(x-4)^2.
    You finish.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Mar 2009
    Posts
    21
    Quote Originally Posted by Plato View Post
    The first derivative is f'(x)=(x-4)^3+3x(x-4)^2.
    You finish.
    Yes I got the first derivative already. I wasn't able to get the 2nd.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    -1
    e^(i*pi)'s Avatar
    Joined
    Feb 2009
    From
    West Midlands, England
    Posts
    3,053
    Thanks
    1
    Quote Originally Posted by sgonzalez90 View Post
    Yes I got the first derivative already. I wasn't able to get the 2nd.
    Use a combination of the product rule and the chain rule. Hint:

    (x-4)^3+3x(x-4)^2 = (x-4)^3 + (3x \times (x-4)^2)
    Follow Math Help Forum on Facebook and Google+

  5. #5
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,614
    Thanks
    1581
    Awards
    1
    You cannot find the derivative of (x-4)^3+3x(x-4)^2?
    You are joking, right?
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Newbie
    Joined
    Mar 2009
    Posts
    21
    Quote Originally Posted by Plato View Post
    You cannot find the derivative of (x-4)^3+3x(x-4)^2?
    You are joking, right?
    I tried this and got a big mess of a problem but this is what i got

    3x-12 (x-4)^2 + (6x^2-24x)^2(x-4)
    Follow Math Help Forum on Facebook and Google+

  7. #7
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,614
    Thanks
    1581
    Awards
    1
    f'(x)=(x-4)^3+3x(x-4)^2

    f"(x)=3(x-4)^2+3(x-4)^2+6x(x-4)

    That is it.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Derivatives and Anti-Derivatives
    Posted in the Calculus Forum
    Replies: 7
    Last Post: February 6th 2011, 06:21 AM
  2. Replies: 1
    Last Post: July 19th 2010, 04:09 PM
  3. Derivatives with both a and y
    Posted in the Calculus Forum
    Replies: 3
    Last Post: October 4th 2009, 09:17 AM
  4. Replies: 4
    Last Post: February 10th 2009, 09:54 PM
  5. Trig derivatives/anti-derivatives
    Posted in the Calculus Forum
    Replies: 1
    Last Post: February 10th 2009, 01:34 PM

Search Tags


/mathhelpforum @mathhelpforum