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!

Checking the answer to complex number question

  1. Sep 20, 2008 #1


    User Avatar
    Homework Helper

    1. The problem statement, all variables and given/known data
    Find an equation connecting x and y for which (z-1)/(z+1) has an argument [itex]\alpha[/itex]

    2. Relevant equations


    3. The attempt at a solution


    Substituting z=x+iy

    [tex]\Rightarrow \frac{z-1}{z+1}=\frac{(x-1)+iy}{(x+1)+iy}[/tex]




    [tex]= \frac{x^2+y^2-1}{(x+1)^2+y^2} +i \frac{2y}{(x+1)^2+y^2}[/tex]


    [tex]tan\alpha = \frac{2y}{x^2+y^2-1}[/tex]

    Is this correct? Or should I just put in the form of a circle?
  2. jcsd
  3. Sep 20, 2008 #2


    User Avatar
    Science Advisor
    Homework Helper

    Hi rock.freak667! :smile:

    Yes, that's messy! :biggrin:

    Definitely put it in the form of a nice circle (x² + (y-a)² = b²)! :wink:
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Checking the answer to complex number question