Results 1 to 4 of 4

Math Help - Simple Integration

  1. #1
    Member Jason Bourne's Avatar
    Joined
    Nov 2007
    Posts
    132

    Simple Integration

    Not sure how to do the following integral, is it integration by parts?





    \int{\frac{e^{{\frac{-1}{x}}}}{x^2}dx}
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member Matt Westwood's Avatar
    Joined
    Jul 2008
    From
    Reading, UK
    Posts
    807
    Thanks
    27
    Naah, try a substitution. Note that d/dx (1/x) = -1/x^2.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Super Member

    Joined
    May 2006
    From
    Lexington, MA (USA)
    Posts
    11,686
    Thanks
    617
    Hello, Jason Bourne!

    \int{\frac{e^{\text{-}{\frac{1}{x}}}}{x^2}dx}

    We have: . \int e^{\text{-}x^{\text{-}1}}\left( x^{\text{-}2}\,dx\right)


    Let: . u = \text{-}x^{\text{-}1}\quad\Rightarrow\quad du \:=\:x^{\text{-}2}dx


    Substitute: . \int e^u\,du\quad\hdots\quad Got\; it?

    Follow Math Help Forum on Facebook and Google+

  4. #4
    Member Jason Bourne's Avatar
    Joined
    Nov 2007
    Posts
    132
    Thank You very much, it's so obvious now.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Simple integration
    Posted in the Calculus Forum
    Replies: 2
    Last Post: October 20th 2011, 12:36 PM
  2. simple integration
    Posted in the Calculus Forum
    Replies: 5
    Last Post: June 14th 2011, 04:07 AM
  3. Replies: 2
    Last Post: February 19th 2010, 10:55 AM
  4. Simple Integration
    Posted in the Calculus Forum
    Replies: 3
    Last Post: January 31st 2009, 04:32 PM
  5. simple integration
    Posted in the Calculus Forum
    Replies: 3
    Last Post: October 20th 2008, 04:49 PM

Search Tags


/mathhelpforum @mathhelpforum