and . "Negative r" would be unusual notation but you would just add or subtract from the angle, A.
(-5,12) are the rectangular coordinates of a point. Find two pairs of polar coordinates (r,A) for each point, on with r>0 and one with r<0. Express A in radians. Please help! please explain process and answer, im working on a similar problem with a tutor and she is not very much help.