$\"\"$

The polar equation is $\"r$ .

Let $\"\"$ be a real number, then the graph of the equation $\"\"$ is a horizontal line.

It lies $\"\"$ units above the pole if $\"\"$ and $\"\"$ units below the pole.

From formulas : $\"\"$ .

$\"y$ .

$\"\"$

Graph :

(1) Draw the polar coordinate plane.

(2) Graph the equation $\"r$ .

Graph of $\"r$ or $\"y$ :

$\"\"$

Observe the graph :

The graph $\"y$ is a horizantal line $\"\"$ units downwards to the pole.

$\"\"$

$\"y$ , horizantal line $\"\"$ units downwards to the pole.

Graph of $\"r$ or $\"y$ :

$\"\"$