find two other pairs of polar coordinates of the given polar coordinate, one with r > 0 and one with r < 0. Then plot the point.
(a) (3, π/2)
(r, θ) = ( ) (r > 0)
(r, θ) = ( ) (r < 0)
(b) (2, -2π/3)
(r, θ) = ( )(r > 0)
(r, θ) = ( )(r < 0)
(c) (-2, π/3)
(r, θ) = ( )(r > 0)
(r, θ) = ( )(r < 0)