Results 1 to 5 of 5

Math Help - Partial Fractions Question

  1. #1
    Super Member
    Joined
    Dec 2008
    Posts
    509

    Partial Fractions Question

    Hi
    Need help to express the following in partial fractions:

    \frac{x^2-2}{(x+1)(x-2)}


    P.S
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Master Of Puppets
    pickslides's Avatar
    Joined
    Sep 2008
    From
    Melbourne
    Posts
    5,236
    Thanks
    28
    What do you need to do with this expression?

    The order of the numerator is the same as the denominator, you may not need to make partial fractions.

    If you need to consider


    \frac{x^2-2}{(x+1)(x-2)} = \frac{A}{x+1}+\frac{B}{x-2}

    x^2-2 = A(x-2)+B(x+1)

    choose values for x to solve for A and B.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,758
    Thanks
    493
    Quote Originally Posted by Paymemoney View Post
    Hi
    Need help to express the following in partial fractions:

    \frac{x^2-2}{(x+1)(x-2)}


    P.S
    \frac{x^2-2}{(x+1)(x-2)} =

    \frac{x^2-2}{x^2-x-2} =

    \frac{x^2-x-2+x}{x^2-x-2} =

    \frac{x^2-x-2}{x^2-x-2} + \frac{x}{x^2-x-2} =

    1 + \frac{x}{(x+1)(x-2)}

    now use the method of partial fractions on \frac{x}{(x+1)(x-2)}
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Super Member
    Joined
    Dec 2008
    Posts
    509
    Quote Originally Posted by skeeter View Post

    \frac{x^2-x-2}{x^2-x-2} + \frac{x}{x^2-x-2} =

    1 + \frac{x}{(x+1)(x-2)}
    Can you explain to me why did you plus \frac{x}{x^2-x-2}
    Follow Math Help Forum on Facebook and Google+

  5. #5
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,758
    Thanks
    493
    Quote Originally Posted by Paymemoney View Post
    Can you explain to me why did you plus \frac{x}{x^2-x-2}

    and then how did you get 1 + \frac{x}{(x+1)(x-2)}
    note that the numerator and denominator of your original fraction have the same degree.

    you can get the same result by dividing x^2-2 by (x+1)(x-2) using long division.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 12
    Last Post: October 2nd 2011, 06:07 AM
  2. partial fractions question
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: September 14th 2010, 11:47 AM
  3. Replies: 0
    Last Post: April 28th 2010, 09:53 AM
  4. Quick Question on Partial Fractions Problem
    Posted in the Algebra Forum
    Replies: 3
    Last Post: March 26th 2010, 09:49 PM
  5. Partial Fractions Question
    Posted in the Algebra Forum
    Replies: 3
    Last Post: March 26th 2010, 04:24 AM

Search Tags


/mathhelpforum @mathhelpforum