1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Integration by Parts

  1. Jan 6, 2008 #1
    1. The problem statement, all variables and given/known data

    Integrate x^2 e^x^3 dx


    2. Relevant equations

    I = uv - integral of u'v

    3. The attempt at a solution

    I don't know where to begin this question at all and have been stuck on it for the past half hour. Any help would be really appreciated. :(
     
  2. jcsd
  3. Jan 6, 2008 #2

    Dick

    User Avatar
    Science Advisor
    Homework Helper

    e^x^3 can mean either e^(x^3) or (e^x)^3. Use parentheses! (If not TeX). If it's the former then d(x^3)=3*x^2, suggest a u substitution.
     
    Last edited: Jan 6, 2008
  4. Jan 6, 2008 #3
    Sorry about that. I'll try again.
     
  5. Jan 6, 2008 #4
    I'm not sure how to use the tags here so I'll just post a picture.
    [​IMG]
     
  6. Jan 6, 2008 #5

    olgranpappy

    User Avatar
    Homework Helper

    that doesn't really help...
     
  7. Jan 6, 2008 #6
    That's how it is in my textbook though.
     
  8. Jan 6, 2008 #7

    Dick

    User Avatar
    Science Advisor
    Homework Helper

    Ok, we'll guess. I think it probably means e^(x^3). Can you suggest a u substitution?
     
  9. Jan 6, 2008 #8

    olgranpappy

    User Avatar
    Homework Helper

    ...in which case, you don't need to "integrate by parts". you just need the substitution which was suggested.

    (which bond girl are you? Ursella Andress?)
     
  10. Jan 6, 2008 #9
    Here's what I have done
    u = x^2
    v = 3x^2 e^(x^3)
    du = 2x dx
    dv = e^(x^3)2x dx

    I = x^2 3x^2 e^(x^3) - integral of 3x^2 e^(x^3)

    I'm not sure how to integrate the 3x^2 e^(x^3).
     
  11. Jan 6, 2008 #10

    olgranpappy

    User Avatar
    Homework Helper

    use the substitution y=x^3 and that's it. just "change variables" not "integrate by parts".
     
  12. Jan 6, 2008 #11
    I'll try that - thanks!!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Integration by Parts
  1. Integration by parts (Replies: 6)

  2. Integration by parts (Replies: 8)

  3. Integration by Parts (Replies: 8)

Loading...