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Homework Statement
Find an equation connecting x and y for which (z-1)/(z+1) has an argument [itex]\alpha[/itex]
Homework Equations
z=x+iy
arg(z)=tan-1(y/x)
The Attempt at a Solution
[tex]\frac{z-1}{z+1}[/tex]
Substituting z=x+iy
[tex]\Rightarrow \frac{z-1}{z+1}=\frac{(x-1)+iy}{(x+1)+iy}[/tex]
Realizing
[tex]\frac{(x+1)(x-1)+iy(x+1)-iy(x-1)-i^2y^2}{(x+1)^2+y^2}[/tex]
Re:i2=-1
[tex]= \frac{x^2+y^2-1}{(x+1)^2+y^2} +i \frac{2y}{(x+1)^2+y^2}[/tex]
Thus
[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?