$\"\"$

Eccentricity of ellipse is $\"\"$ .

Directrix of ellipse is $\"\"$ .

$\"\"$

Relation between the polar and rectangular coorinates: $\"\"$ and $\"\"$ .

$\"\"$ .

Thus, directrix line is $\"\"$ .

$\"\"$

Standard form of ellipse with directrix $\"\"$ is $\"\"$ .

Eccentricity of ellipse is $\"\"$ .

Substitute $\"\"$ and $\"\"$ in standard form.

$\"\"$

$\"\"$ .

The polar equation of the ellipse is $\"\"$ .

$\"\"$

The polar equation of the ellipse is $\"\"$ .