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 of <C> i just cannot do

  1. Jun 4, 2005 #1
    Can anyone outline, and this is a rather large request, the step by step integration by parts for <C>? This is not a homework question but more something i need to be able to do on tuesday for my final, and have been trying to do for two days.

    Attached Files:

  2. jcsd
  3. Jun 4, 2005 #2


    User Avatar
    Science Advisor
    Homework Helper

    Your answer is incorrect.

    Here's how it's done.

    Knowing this integral's value

    [tex] I'_{1}(\alpha)=:\int_{0}^{+\infty} C e^{-\alpha C^{2}} \ dC =\frac{1}{2\alpha} [/tex] (1)

    ,one sees immediately that

    [tex] I'_{3}(\alpha)=:\int_{0}^{+\infty} C^{3} e^{-\alpha C^{2}} \ dC=-\frac{d}{d\alpha}I'_{1}=\frac{1}{2\alpha^{2}} [/tex] (2)

    and now plug in (2) the expression for '\alpha'.

  4. Jun 4, 2005 #3
    Thank you, and you're right, i forgot to type the pi in the denominator for the answer.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Integration by Parts of <C> i just cannot do