The eccentricity of a conic is .
Vertices of the conic is at and
.
Because eccentricity is , the conic is an ellipse.
The center of the ellipse is at , the midpoint of the segment between the given vertices.
Therefore the directrix will be in the left side of the pole i.e. at .
The polar equation of the conic with the directrix is .
Find the value of :
Use the value of and the polar form of a point on the conic to determine the value of
.
The vertex has polar coordinates
.
.
.
.
The equation in standard form : .
Polar form of the conic with directrix is .
Substitute and
in standard form.
Therefore, the equation of the ellipse is .
By simplifying .
Therefore, the polar equation is .
Because , the equation of the directrix is
.
(1) Draw the coordinate plane.
\(2) Graph the polar equation .
Graph :
\
Observe the graph,
\The polar equation is an ellipse.
\The polar equation is .
The polar equation is an ellipse.
\Graph :
\