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!

Complex expressions

  1. Oct 11, 2013 #1
    Hello I'm studying complex numbers for class and the question is stated as:
    Let z=1+2i
    Find:
    a) 1/z^2
    b) 1/z^3

    I was thinking just to multiply by the conjugate (1-2i)^2 for (a) and similarly for (b).
    Would that be correct in solving it?
     
  2. jcsd
  3. Oct 11, 2013 #2

    mfb

    User Avatar
    2016 Award

    Staff: Mentor

    You can do that, right.
    Alternatively, calculate 1/z first, and then calculate powers of that.

    As this looks like homework, I moved your thread.
     
  4. Oct 11, 2013 #3
    Oh thank you!
    I apologize if I put it in the wrong thread!
     
  5. Oct 12, 2013 #4
    Firstly, let's establish what you are actually asking.

    For example, the way you wrote it, 1/z^2 = [itex]\frac{1}{z^2}[/itex], NOT [itex](\frac{1}{z})^2[/itex]

    EDIT: Please ignore. Complete brain-fart by me there! :redface:
     
    Last edited: Oct 12, 2013
  6. Oct 12, 2013 #5

    mfb

    User Avatar
    2016 Award

    Staff: Mentor

    Where is the difference?
     
  7. Oct 12, 2013 #6
    Thanks. I simply cannot believe what I wrote in my previous post.

    I blame lack of sleep...:zzz:
     
  8. Oct 12, 2013 #7

    HallsofIvy

    User Avatar
    Staff Emeritus
    Science Advisor

    Surely there must be some way to completly delete a post so that those of us who post a really stupid idea can pretend it never happened!?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Complex expressions
Loading...