SOLUTION
To find the additional polar representation of a giving point we use the following
1. By adding or subtracting a multiple of 2π to θ
2. By using a negative radius r, and adding an odd multiple to π
Giving the polar coordinates

The additional coordination will be by adding 2π to θ

Hence one addition coordinate is (6,17π/6)
To find additional polar coordinates,
We subtract 2π from θ

Hence, another additional coordinate is (6,-7π/6 )
Therefore, the two additional polar coordinates are (6,17π/6) and (6,-7π/6 )