Let C0 be a circle that passes through the points 1 and −1 and has center c0=ia.
(a) Find the equation of the circle C0.
(b) Show that the image of the circle C0 under w=z+1z−1 is a line L0 that passes through the origin.
(c) Show that the line L0 is inclined at the angle α0=2π−Arctan(a).