Question

Which set of rectangular coordinates describes the same location as the polar coordinates (-2, 2pi)

A. (0,2)
B. (-2,0)
C. (2,0)
D. (0,-2)

Answer 1

To answer this question you should know what to do to change the polar coordinates to rectangular ones: x = rcos (θ)
 y = rsen (θ)
 So for r = -2 and θ = 2π we have

 x = -2cos (2π)
 x = -2

 y = -2sen (2π)
 y = 0
 Finally the equivalent point in Cartesian coordinates is the point:
 (-2 0)
 
 The correct answer is option B