1.If z−αz+α\dfrac{z - \alpha}{z + \alpha}z+αz−α (where α∈R\alpha \in \mathbb{R}α∈R) is a purely imaginary number and ∣z∣=2|z| = 2∣z∣=2, then a value of α\alphaα is:a.111b.12\dfrac{1}{2}21c.2\sqrt{2}2d.222Login to continueOnly logged in users canattempt or see the solution.
