A complex number z is said to be unimodular if . Suppose `z_1` and `z_2` are complex numbers...

complex number z is said to be unimodular if . Suppose `z_1`
and `z_2`
are complex numbers such that `(z_1-2z_2)/(2-z_1z_2)`
is unimodular and `z_2`
is not unimodular. Then the point `z_1`
lies
on a :
(1)
straight line parallel to x-axis
(2) straight line parallel to y-axis
(3)
circle of radius 2
(4) circle of radius `sqrt(2)`