(a) Find the polar coordinates of the points whose cartesian coordinates are (1, 2), (–1, 3), (–1, –1), (1, –2), (1, 0), (0, 2), (0, –2). 

(b) Find the cartesian coordinates of the points whose polar coordinates are (3, π/4), (2, –π/6), (2, –π/2), (5, 3π/4).