The Cartesian coordinates of a point are given. (i) Find polar coordinates (r, ) of the point,

The Cartesian coordinates of a point are given.
(i) Find polar coordinates (r, θ)  of the point, where r > 0 and 0 < θ, 2π.
(ii) Find polar coordinates (r, θ) of the point, where r < 0 and 0 < θ, 2π.

(a) (√3 , -1) 

(b) (-6, 0)