$\"\"$

\

The equation is $\"\"$ .

\

The polar coordinates are related to Cartesian coordinates by the equation $\"\"$ .

\

Where $\"\"$ .

\

Change the polar equation into Cartesian equation.

\

$\"\"$

\

Multiply each side by $\"\"$ .

\

$\"\"$ .

\

Substitute $\"\"$ and $\"\"$ .

\

$\"\"$ .

\

$\"\"$ . $\"\"$

\

Change the expressions $\"\"$ into a perfect square trinomial,

\

add $\"\"$ and add $\"\"$ to each side of the equation.

\

$\"\"$

\

$\"\"$

\

Compare above equation with circle standard equation $\"\"$ .

\

Where $\"\"$ is center of circle and $\"\"$ is the radius of circle.

\

The equation $\"\"$ is in the form of circle equation $\"\"$ .

\

Center of circle is $\"\"$ .

\

Radius of circle is $\"\"$ .

\

$\"\"$

\

The circle equation is $\"\"$ .

\

Center of circle is $\"\"$ .

\

Radius of circle is $\"\"$ .