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 Problem

  1. Aug 27, 2007 #1
    Hi
    I'm trying to integrate
    [tex]
    \int (-40x^3 + 38.4x^2 - 13.288x + 1.98072)\sqrt{14400x^4 - 18432x^3 + 9087.36x^2 - 2041.0368x+ 177.570944}dx
    [/tex]
    The way I thought I could do it was express the first part (the cubic) in terms of the derivative of the second and do it by substitution. Unfortunately it doesn't work. :frown:
    Not totally sure that it can be done at all.

    Thanks for any help!
     
  2. jcsd
  3. Aug 27, 2007 #2

    Dick

    User Avatar
    Science Advisor
    Homework Helper

    No, I don't think you are going to be able to integrate that in closed form. But there are simple numerical methods to consider like Simpson's rule.
     
  4. Aug 27, 2007 #3
    You can painfully do it by elliptic intehrals. But how did you arrive at this problem?
     
  5. Aug 27, 2007 #4
    I put it into maple, and the answer cannot be expressed with elementary functions (and the answer is about 19 lines!)
     
  6. Aug 28, 2007 #5
    Ok thanks people. I found the answer numerically. I arrived at the problem when trying to evaluate the surface of revolution of the cubic function.
     
  7. Aug 28, 2007 #6

    Gib Z

    User Avatar
    Homework Helper

    How did you evaluate an indefinite integral numerically :(
     
  8. Aug 28, 2007 #7
    Haha it was a definite integral, just didn't bother with the notation :-)
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Integration Problem
  1. Integration problem (Replies: 4)

  2. Integral Problem (Replies: 31)

  3. Integration problem (Replies: 9)

  4. Integration Problem (Replies: 7)

Loading...