Results 1 to 4 of 4

Math Help - An integral

  1. #1
    Newbie
    Joined
    Dec 2008
    Posts
    4

    Thumbs down An integral

    How would you to integrate:
    1/[x^2* ((1+x^3)^(2/3))]
    Thanks
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member
    Joined
    Jun 2008
    Posts
    792
    Use a reciprocal substitution such as u=\frac{1}{x}
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Dec 2008
    Posts
    4
    Quote Originally Posted by Chop Suey View Post
    Use a reciprocal substitution such as u=\frac{1}{x}
    I 've tried this way before but it seems to be not effective.
    Could you solve it more detailed?
    Thanks
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Super Member
    Joined
    Jun 2008
    Posts
    792
    \int \frac{1}{x^2(1+x^3)^{\frac{2}{3}}}~dx

    Subbing u = \frac{1}{x} \implies du = -\frac{1}{x^2}~dx switches the integral to:
    -\int \frac{1}{(1+\frac{1}{u^3})^{\frac{2}{3}}}~du=-\int \frac{1}{(\frac{u^3+1}{u^3})^{\frac{2}{3}}}~du = -\int \frac{u^2}{(u^3+1)^{\frac{2}{3}}}~du

    You should pick this up right away.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 2
    Last Post: August 31st 2010, 08:38 AM
  2. Replies: 1
    Last Post: June 2nd 2010, 03:25 AM
  3. Replies: 0
    Last Post: May 9th 2010, 02:52 PM
  4. Replies: 0
    Last Post: September 10th 2008, 08:53 PM
  5. Replies: 6
    Last Post: May 18th 2008, 07:37 AM

Search Tags


/mathhelpforum @mathhelpforum