1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    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!

Integral and complex exponential question: my physics teacher just gives me math hw

  1. Oct 22, 2006 #1
    I have two homework problems that have been driving me nuts:

    1.) evaluate the indefinite integral:


    where a and b are real positive constants. I just don't know where to start on it.

    2.) Find all values of i^(2/3)

    So far I have:

    = e^(2/3*ln(i))
    = e^(2/3*i*(Pi/2 + 2*n*Pi))
    = e^(i*Pi/3)*e^(i*n*4Pi/3)

    I know from the back of my book my three solutions should end up being (1+i*sqrt(3))/2, (1-i*sqrt(3))/2, -1. But I can't seem to get there. I'd really appreciate any help. Sorry if my shorthand is confusing.
  2. jcsd
  3. Oct 22, 2006 #2
    For 1) use the exponential notation for cos x, then integrate. You can do it by integration by parts twice, then use 'the trick' but that would be pretty messy.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Threads - Integral complex exponential Date
Line Integrals Complex Numbers Oct 19, 2008
Complex integration Apr 25, 2008
A complex integral from the text Sep 28, 2005
Complex integral Sep 25, 2005
Integral / Complex Nos. Feb 17, 2005