calculating Hyperbolic distance

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To calculate the hyperbolic distance we use the formula $$\left|\frac{w-z}{1-\bar wz}\right|$$

I want to apply this to the following pair of points:

\begin{align*} w&=\frac{-1}{\sqrt{3}}\space +\space \frac{1}{\sqrt{3}}i \\ z&=\frac{1}{\sqrt{3}}\space +\space \frac{1}{\sqrt{3}}i \\ \left|\frac{w-z}{1-\bar wz}\right| &= \frac{\left(\frac{-1}{\sqrt{3}}+\frac{1}{\sqrt{3}}i\right)-\left(\frac{1}{\sqrt{3}}+\frac{1}{\sqrt{3}}i\right)}{1-\left(-\frac{1}{\sqrt{3}}-\frac{1}{\sqrt{3}}i\right)\left(\frac{1}{\sqrt{3}}+\frac{1}{\sqrt{3}}i\right)} \\ &=\frac{2\sqrt{3}}{1-\frac{1}{3}\left(1+i\right)^2} \\ &=\frac{2\sqrt{3}}{\sqrt{13}} \end{align*}

I am not sure how you get from the penultimate step to the final step. Could someone explain in depth how this was done? Thanks

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Wikipedia gives the formula for the distance in the Poincaré disk model:

$$d=\operatorname{arcosh}\left(1+2\frac{\lvert z-w\rvert^2}{\left(1-\lvert z\rvert^2\right)\left(1-\lvert w\rvert^2\right)}\right)= \operatorname{arcosh}(1+2\cdot12)=\operatorname{arcosh}25\approx3.9116$$

Your formulas are different from this, and the penultimate one has several errors as well: it lacks the absolute value bars, and it has a sign wrong in the denominator, and a wrong numerator as well.

\begin{align*} \left\lvert\frac{w-z}{1-\bar wz}\right\rvert &= \left\lvert \frac{\left(\frac{-1}{\sqrt{3}}+\frac{1}{\sqrt{3}}i\right)-\left(\frac{1}{\sqrt{3}}+\frac{1}{\sqrt{3}}i\right)}{1-\left(-\frac{1}{\sqrt{3}}-\frac{1}{\sqrt{3}}i\right)\left(\frac{1}{\sqrt{3}}+\frac{1}{\sqrt{3}}i\right)} \right\rvert \\&= \left\lvert\frac{-\frac2{\sqrt{3}}}{1+\frac{1}{3}\left(1+i\right)^2}\right\rvert = \left\lvert\frac{-\frac2{\sqrt3}}{1+\frac23i}\right\rvert = \left\lvert\frac{-\frac2{\sqrt3}\left(1-\frac23i\right)}{\left(1+\frac23i\right)\left(1-\frac23i\right)}\right\rvert \\&= \left\lvert\frac{-\frac2{\sqrt3}\left(1-\frac23i\right)}{1+\frac49}\right\rvert = \left\lvert\frac{\left(-\frac2{\sqrt3}\left(1-\frac23i\right)\right)\cdot9}{\left(1+\frac49\right)\cdot9}\right\rvert = \left\lvert\frac{-2\sqrt3\left(3-2i\right)}{9+4}\right\rvert \\&= \left\lvert\frac{2\sqrt3}{13}(-3+2i)\right\rvert = \frac{2\sqrt3}{13}\cdot\left\lvert-3+2i\right\rvert = \frac{2\sqrt3}{13}\sqrt{3^2+2^2} = \frac{2\sqrt3}{13}\sqrt{13} = \frac{2\sqrt3}{\sqrt{13}} \end{align*}