$\"\"$

Observe the garph :

The graph is a circle centered at the origin with radius $\"\"$ , or the set of all points that are

$\"\"$ from the pole.

This set of points take on the form $\"\"$ , where $\"\"$ is any real number.

Two equations match this description : $\"\"$ and $\"\"$ .

The graph is a circle cuts the origin at $\"\"$ and $\"\"$ .

$\"\"$

The equations are $\"\"$ and $\"\"$ .