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!

Simple exponential question

  1. Dec 17, 2007 #1
    I'm currently learning complex analysis, and there's something I can't quite get...

    Code (Text):
    e^2 * e^3 = e^(2+3) = e^5
    So why is that:
    Code (Text):
    e^(i*PI*t) * e^(i*PI) = -e^(i*PI*t)

    I was able to get the solution from:
    Code (Text):
    e^(i*PI*t) * e^(i*PI) =
      = (Cos(PI*t) + iSin(PI*t)) * (Cos(PI) + iSin(PI)) =
      = (Cos(PI*t) + iSin(PI*t)) * (-1) =
      = -e^(i*PI*t)
    But, what am I missing? :redface:

  2. jcsd
  3. Dec 17, 2007 #2
    I don't think you are missing anything, it is just another way to say the same thing.

    e^{i\pi t}e^{i\pi}=e^{i\pi t+i\pi}=-e^{i\pi t}

    Because as you have derived yourself
  4. Dec 17, 2007 #3
    Hm, I see.

    The first time I came across this I just assumed:
    e^{i\pi t}e^{i\pi}=e^{i\pi t+i\pi}=e^{i\pi (t+1)}
    was the simplest way it could get.

    Well, thanks again! :smile:
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Simple exponential question
  1. Simple question (Replies: 6)

  2. Simple question (Replies: 4)

  3. Simple Question (Replies: 1)