1.
For α,β,z∈C\alpha, \beta, z \in \mathbb{C} and λ>1\lambda > 1, if λ2−1\sqrt{\lambda^2 - 1} is the radius of the circle ∣z−α∣2+∣z−β∣2=λ2|z - \alpha|^2 + |z - \beta|^2 = \lambda^2, then ∣α−β∣|\alpha - \beta| is equal to: