1. Limited time only! Sign up for a free 30min personal 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!

Homework Help: Integral from e to infinity

  1. Feb 20, 2009 #1
    1. The problem statement, all variables and given/known data

    integral [from e to infinity of ] 67 / (x(ln(x))^3)

    read as the integral from e to infinity of

    67 divided by x times cubed lnx.

    2. Relevant equations

    3. The attempt at a solution

    i know it converges,

    but i got the value

  2. jcsd
  3. Feb 21, 2009 #2
    Re: divergent/convergent

    And I would agree with you...

    Using the substitution [tex]u=\ln{x}[/tex], the integral

    [tex]\int_e^\infty \frac{1}{x(\ln{x})^3} \, dx[/tex]


    [tex]-\frac{1}{2} \int_1^\infty \frac{1}{u^2} \, du.[/tex]
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook