Results 1 to 6 of 6

Math Help - Differentiating a fraction

  1. #1
    Newbie
    Joined
    Jan 2008
    Posts
    3

    Question Differentiating a fraction

    ok i have this question and need some urgent help, i have to hand this in tomorrow and im rapidly falling very tired;

    i am studying AS level mathematics on the aqa syllabus...


    i have this question for homework:

    A curve has the equation: Y= X^4/4 + 32/X^2

    A: find dy/dx

    i dont simply want the answer is it possible for anyone to give me a worked solution?


    thnx in advance: Smithswood
    Last edited by Smithswood; January 23rd 2008 at 12:50 PM.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by Smithswood View Post
    ok i have this question and need some urgent help, i have to hand this in tomorrow and im rapidly falling very tired;

    i am studying AS level mathematics on the aqa syllabus...


    i have this question for homework:

    A curve has the equation: Y= X^4/4 + 32/X^2

    A: find dy/dx

    i dont simply want the answer is it possible for anyone to give me a worked solution?


    thnx in advance: Smithswood
    y = \frac{x^4}{4} + \frac{32}{x^2} = \frac{x^4}{4} + 32 x^{-2}.

    Now apply the well known rule (to each term) that the derivative of a x^n is n a x^{n-1}.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Jan 2008
    Posts
    3

    so...?

    so \frac{x^4}{4}

    would become 4x^3

    and how did you get 32x^-2?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Senior Member
    Joined
    Jan 2008
    From
    UK
    Posts
    484
    Thanks
    66
    Quote Originally Posted by Smithswood View Post
    so \frac{x^4}{4}
    would become 4x^3
    No it would become \frac{4x^3}{4}=x^3



    Quote Originally Posted by Smithswood View Post
    and how did you get 32x^-2?
    \frac{a}{b^n}=ab^{-n}
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Newbie
    Joined
    Jan 2008
    Posts
    3

    therefore...

    would it not be 32x^-1

    as 32 = 32x^1?

    1 - 2 = -1???
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Senior Member
    Joined
    Jan 2008
    From
    UK
    Posts
    484
    Thanks
    66
    Quote Originally Posted by Smithswood View Post
    would it not be 32x^-1
    No \frac{32}{x^2}=32x^{-2} Note, this has not been differentiated yet.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Simplifying fraction over fraction expression
    Posted in the Algebra Forum
    Replies: 3
    Last Post: October 17th 2010, 03:27 PM
  2. differentiating partial fraction
    Posted in the Calculus Forum
    Replies: 19
    Last Post: April 9th 2010, 12:13 PM
  3. please help improper fraction into partial fraction
    Posted in the Pre-Calculus Forum
    Replies: 7
    Last Post: March 1st 2010, 10:06 AM
  4. Replies: 2
    Last Post: September 28th 2009, 08:18 PM
  5. Replies: 4
    Last Post: September 1st 2007, 12:05 AM

Search Tags


/mathhelpforum @mathhelpforum