Results 1 to 3 of 3
Like Tree1Thanks
  • 1 Post By Prove It

Math Help - u substitution help -- lots of e^x

  1. #1
    Newbie
    Joined
    Apr 2012
    From
    canada
    Posts
    2

    Question u substitution help -- lots of e^x

    hi there,

    I need help solving the following problem using U-substitution:

    any idea what I should set my u variable equal to?

    any help would be greatly appreciated

    thanks so much & all the best
    - xecutioner
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    11,786
    Thanks
    1570

    Re: u substitution help -- lots of e^x

    Quote Originally Posted by xecutioner View Post
    hi there,

    I need help solving the following problem using U-substitution:

    any idea what I should set my u variable equal to?

    any help would be greatly appreciated

    thanks so much & all the best
    - xecutioner
    Let \displaystyle \begin{align*} u = e^x + 4 \implies du = e^x\,dx \end{align*} and the integral becomes

    \displaystyle \begin{align*} \int{\frac{e^x}{\left(e^x + 4\right)^3}\,dx} &= \int{\frac{1}{u^3}\,du} \\ &= \int{u^{-3}\,du} \end{align*}

    I'm sure you can go from here
    Thanks from princeps
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Apr 2012
    From
    canada
    Posts
    2

    Re: u substitution help -- lots of e^x

    hi there,

    your post has helped me significantly, thanks so much!

    all the best,

    xecutioner
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Lots of questions
    Posted in the Discrete Math Forum
    Replies: 2
    Last Post: November 27th 2009, 08:27 PM
  2. Need lots of help! :D
    Posted in the Geometry Forum
    Replies: 2
    Last Post: June 6th 2009, 11:46 AM
  3. Need lots of help for test
    Posted in the Algebra Forum
    Replies: 3
    Last Post: April 20th 2009, 01:01 PM
  4. Lots Of Help Please!! Asap!
    Posted in the Calculus Forum
    Replies: 6
    Last Post: May 12th 2008, 05:44 AM
  5. I need lots of help, please!
    Posted in the Math Topics Forum
    Replies: 5
    Last Post: October 3rd 2006, 04:44 PM

Search Tags


/mathhelpforum @mathhelpforum