Answer
Step I: Add $2\pi $ to the angle and keep r unchanged.
Step II: Add $\pi $ to the angle and replace r with $-r$.
Work Step by Step
Consider a point $\left( r,\theta \right)$. To find two additional sets of polar coordinates for the point $\left( r,\theta \right)$ we need to follow the steps given below:
Step I: Add $2\pi $ to the angle and keep r unchanged.
Step II: Add $\pi $ to the angle and replace r with $-r$.
For example, consider a point $\left( 2,\frac{\pi }{3} \right)$.
Its two additional sets obtained by the steps given above are,
$\left( 2,\frac{7\pi }{3} \right)$ from Step I and $\left( -2,\frac{4\pi }{3} \right)$ from Step II.
