Results 1 to 3 of 3

Math Help - Integration with partial fractions

  1. #1
    Member
    Joined
    Jan 2009
    From
    London
    Posts
    92

    Question Integration with partial fractions

    hi - I've got some revision questions ready for my easter exams and I'm having issues with this one:

    Find the values of A,B & C

    2 + 3x / ( ( 1+ x )^2)(4 + 3x) = A/(1 +x) + B/(1+x)^2 + C/(4 + 3x)

    Pretty simple stuff an I get A = 6 , B = -1 & C = -18

    It then asks to integrate the function with in the limits of 4 & 3 and show that it is equal to:

    6ln(35/32) - 3/10

    but I get 6ln(65/64) - 1/20

    I can't see if I'm wrong or if the question is wrong... I know what is more probable so any advice would be grateful

    Thanks, D
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,629
    Thanks
    430
    Quote Originally Posted by dojo View Post
    hi - I've got some revision questions ready for my easter exams and I'm having issues with this one:

    Find the values of A,B & C

    2 + 3x / ( ( 1+ x )^2)(4 + 3x) = A/(1 +x) + B/(1+x)^2 + C/(4 + 3x)

    Pretty simple stuff an I get A = 6 , B = -1 & C = -18

    It then asks to integrate the function with in the limits of 4 & 3 and show that it is equal to:

    6ln(35/32) - 3/10

    but I get 6ln(65/64) - 1/20

    I can't see if I'm wrong or if the question is wrong... I know what is more probable so any advice would be grateful

    Thanks, D
    my TI-89 agrees with your solution if the original definite integral is

    \int_3^4 \frac{2+3x}{(1+x)^2 (4+3x)} \, dx
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Jan 2009
    From
    London
    Posts
    92
    Thanks - I'll bring it up with my Calculus teacher tomorrow.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Partial Fractions/ Integration
    Posted in the Calculus Forum
    Replies: 2
    Last Post: December 13th 2010, 03:53 PM
  2. Integration by partial fractions?
    Posted in the Calculus Forum
    Replies: 8
    Last Post: October 22nd 2009, 09:03 AM
  3. integration using partial fractions
    Posted in the Calculus Forum
    Replies: 1
    Last Post: February 4th 2009, 02:26 AM
  4. Integration using partial fractions
    Posted in the Calculus Forum
    Replies: 1
    Last Post: January 16th 2009, 10:34 AM
  5. Integration by partial fractions
    Posted in the Calculus Forum
    Replies: 4
    Last Post: March 8th 2007, 01:42 PM

Search Tags


/mathhelpforum @mathhelpforum