Answer:
(-9, π/5 + (2n + 1)π)
Step-by-step explanation:
Adding any integer multiple of 2π to the direction argument will result in full-circle rotations, which are identities, so this family is equivalent to the give coordinates:
(9, π/5 + 2nπ), for any integer n
Also, multiplying the radius by -1 is a point reflection, equivalent to a half-turn rotation. Then add π to the direction for another half turn, and the result is another identity. So this too is equivalent to the given coordinates:
(-9, π/5 + (2n + 1)π), for any integer n
