Results 1 to 2 of 2

Math Help - nth derivative

  1. #1
    Newbie
    Joined
    May 2010
    Posts
    8

    nth derivative

    I can't figure this out.
    i need the nth derivative.
    y=(x^2+x-1)/(x-1)
    f'x = (x^2-2*x)/(x-1)^2
    f''x = 2/(x-1)^3
    f'''x = -6/(x-1)^4
    f''''x = 24/(x-1)^5
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member Failure's Avatar
    Joined
    Jul 2009
    From
    Zürich
    Posts
    555
    Quote Originally Posted by alexgo View Post
    I can't figure this out.
    i need the nth derivative.
    y=(x^2+x-1)/(x-1)
    f'x = (x^2-2*x)/(x-1)^2
    f''x = 2/(x-1)^3
    f'''x = -6/(x-1)^4
    f''''x = 24/(x-1)^5
    Note that f(x)=\frac{x^2+x-1}{x-1}=x+2+\frac{1}{x-1}.
    Thus, appart from the 0th and the 1st derivative, you have f^{(n)}(x)=\frac{d^n}{dx^n}\frac{1}{x-1}=\frac{(-1)^n n!}{(x-1)^{n+1}}
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. contuous weak derivative $\Rightarrow$ classic derivative ?
    Posted in the Differential Geometry Forum
    Replies: 2
    Last Post: April 22nd 2011, 02:37 AM
  2. Replies: 0
    Last Post: January 24th 2011, 11:40 AM
  3. [SOLVED] Definition of Derivative/Alt. form of the derivative
    Posted in the Calculus Forum
    Replies: 2
    Last Post: September 23rd 2010, 06:33 AM
  4. Derivative of arctan in a partial derivative
    Posted in the Calculus Forum
    Replies: 3
    Last Post: September 12th 2010, 01:52 PM
  5. Replies: 2
    Last Post: November 6th 2009, 02:51 PM

Search Tags


/mathhelpforum @mathhelpforum