$\"\"$

The equation is $\"\"$ .

Take tangent on both sides.

$\"\"$ .

From circular function definitions: $\"\"$ , where $\"\"$ is an angle.

$\"\"$ .

$\"\"$

The graph of this equation is a line through the origin with slope $\"\"$ .

$\"\"$

Evaluate the function for several values of $\"\"$ in its domain and use this points to graph the function.

Graph :

(1) Draw the coordinate plane.

(2) Graph the function $\"\"$ . \ \

$\"\"$

$\"\"$

The rectangular equation is $\"\"$ .

Graph of the function $\"\"$ is \ \

$\"\"$